Perchloric acid

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

Study period:

02 April - 23 June 2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.10 (Mutagenicity - In Vitro Mammalian Chromosome Aberration Test)

Deviations:

no

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:

Sodium perchlorate

EC Number:

231-511-9

EC Name:

Sodium perchlorate

Cas Number:

7601-89-0

Molecular formula:

ClHO4.Na

IUPAC Name:

sodium perchlorate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Anhydrous Sodium Perchlorate
- Physical state: white powder
- Analytical purity: 98.21%
- Impurities (identity and concentrations): Not reported
- Purity test date: 10 January 2008
- Lot/batch No.: 10/01/08 GRL 0005/08
- Expiry date of the lot/batch: February 2010
- Storage condition of test material: Room temperature

Method

Target gene:

Not applicable

Species / strain

Species / strain / cell type:

lymphocytes: human

Details on mammalian cell type (if applicable):

Human lymphocytes are primary cell cultures recommended by international regulations for the mammalian chromosome aberration test; they have a stable karyotype with 46 chromosomes and an average cell cycle time of 12-14 hours.
Human lymphocytes were prepared from whole blood samples obtained from two healthy donors and collected into heparinized sterile tubes.

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

liver metabolizing system (S9 mix), obtained from rats previously treated with Aroclor 1254.

Test concentrations with justification for top dose:

First experiment: 39.06, 78.13, 156.3, 312.5, 625, 1250, 2500 and 5000 µg/mL both with and without S9 mix
Second experiment: 156.3, 312.5, 625, 1250 and 5000 µg/mL both with and without S9 mix

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water for injections Batch Nos. IVE14A and IVK26A Supplier: Fresenius Kabi France (92316 Sevres, France).
- Justification for choice of solvent/vehicle:

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

water for injection

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: mitomycin C (without S9), cyclophosphamide (with S9)

Details on test system and experimental conditions:

METHOD OF APPLICATION: For each culture, heparinized whole blood was added to culture medium containing a mitogen (phytohemagglutinin) and incubated at 37°C, for 48 hours.

DURATION
- Preincubation period: 48 hours
- Exposure duration: 3 hours (first experiment +/- S9)
3 hours +S9 and 20 hours -S9 (second experiment) and 44 hours -S9
- Expression time (cells in growth medium): one and half hours
- Selection time (if incubation with a selection agent):
- Fixation time (start of exposure up to fixation or harvest of cells):


SELECTION AGENT (mutation assays):
SPINDLE INHIBITOR (cytogenetic assays): colcemid
STAIN (for cytogenetic assays): none


NUMBER OF REPLICATIONS:2


NUMBER OF CELLS EVALUATED: 100


DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other:
Mitotic index

OTHER EXAMINATIONS:
- Determination of polyploidy: no
- Determination of endoreplication:no
- Other:

Evaluation criteria:

A reproducible and statistically significant increase in the frequency of cells with structural chromosome aberration 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:

For each test and for each harvest time, the frequency of cells with structural chromosome aberration (excluding gaps) in treated cultures was compared to that of the vehicle control cultures. If necessary, the results were compared using the χ2 test, in which p = 0.05 was used as the lowest level of significance.

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 examined

Positive controls validity:

valid

Additional information on results:

In the culture medium, the dose-level of 5000 μg/mL showed no precipitate. At this dose-level,
the pH and the osmolality values were equivalent to those of the vehicle control culture.
With a treatment volume of 100 μL/5.5 mL culture medium, the treatment-levels were as
follows:
⋅ 39.06, 78.13, 156.3, 312.5, 625, 1250, 2500 and 5000 μg/mL, for the first experiment, both
with and without S9 mix,
⋅ 156.3, 312.5, 625, 1250, 2500 and 5000 μg/mL, for the second experiment, both with and
without S9 mix.
The frequency of cells with structural chromosome aberrations of the vehicle and positive
controls was as specified in acceptance criteria. The study was therefore considered valid.
Experiments without S9 mix:
Cytotoxicity:
Following the 3-hour treatment, some slight decreases in mitotic index were noted, without any
clear evidence of a dose-level relationship (up to 31% decrease).
Following the 20-hour treatment, slight to moderate decreases in mitotic index were noted at
dose-levels ≥ 2500 μg/mL (28 to 54% decrease).
Following the 44-hour treatment, slight to moderate decreases in mitotic index were noted at
dose-levels ≥ 1250 μg/mL (32 to 54% decrease).
The dose-levels selected for metaphase analysis were as follows:
⋅ 1250, 2500 and 5000 μg/mL, for the 3-hour and the 20-hour treatments,
⋅ 5000 μg/mL, for the 44-hour treatment.
No significant increase in the frequency of cells with structural chromosomal aberrations was
noted after 3-, 20- as well as 44-hour treatments.
Experiments with S9 mix:
Cytotoxicity:
At the 20-hour harvest times, slight to marked decreases in mitotic index were noted without
any clear evidence of a dose-level relationship (up to 61% decrease).
At the 44-hour harvest time, no noteworthy decrease in mitotic index was noted.
Metaphase analysis:
The dose-levels selected for metaphase analysis were as follows:
⋅ 1250, 2500 and 5000 μg/mL, for the 20-hour harvest time in both experiments,
⋅ 5000 μg/mL, for the 44-hour harvest time.
No significant increase in the frequency of cells with structural chromosomal aberrations was
noted in either experiments and at any harvest times.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

All the data were presented in tabular form in which the type of structural chromosome aberration, the total number of aberrations and the frequency of cells with structural chromosome aberration (including and excluding gaps), are shown. A cell having one or more of the above-mentioned structural chromosome aberration was recorded as a single cell with structural chromosome aberration. Therefore the total frequency of cells with structural chromosome aberration was not necessarily equivalent to the total number of aberrations.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Under these experimental conditions, the test item ANHYDROUS SODIUM PERCHLORATE (batch No. Lot moyen du 10/01/08 test; purity: 98.21%) did
not induce chromosome aberrations in cultured human lymphocytes.

Executive summary:

A study was conducted at CIT Laboratories France to evaluate the potential of the test item Anydrous Sodium Perchlorate to induce chromososome aberrations in cultured human lymphocytes. The study was performed according to international guidelines and in compliance with the principles of GLP. The test item was tested in two independent experiments, both with and without a liver metabolizing system (S9 mix), obtained from rats previously treated with Aroclor 1254. Under the experimental conditions, anhydrous sodium perchlorate did not induce chromosome aberrations in cultured human lymphocytes.