reaction mass of sodium acetate, monoethylene glycol and diethylene glycol

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:

supporting study

Study period:

1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

No detailed information on the number of concentrations tested, only maximum dose reported. No information on replicates.

Data source

Reference

Reference Type:

publication

Title:

Primary Mutagenicity Screening of Food Additives Currently Used in Japan.

Author:

Ishidate M. Jr., T. Sofuni, K. Yoshikawa, M. Hayashi, T. Nohmi, M. Sawada, and A. Matsuoka.

Year:

1984

Bibliographic source:

Food Chem. Toxicol. 22: 623-636.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Deviations:

yes

Remarks:

, no metabolic activation used.

GLP compliance:

not specified

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

Sodium acetate

EC Number:

204-823-8

EC Name:

Sodium acetate

Cas Number:

127-09-3

Molecular formula:

C2H4O2.Na

IUPAC Name:

sodium acetate

Details on test material:

- Test substance: sodium acetate, anhydrous
- Supplied by Japanese Food Additives Association where purity checked before use.

Method

Species / strain

Species / strain / cell type:

mammalian cell line, other: Chinese hamster lung fibroblasts

Details on mammalian cell type (if applicable):

The cell line was originally established from the lung of a newborn female at the Cancer Research Institute, Tokyo (Koyama, Utakoji & Ono, 1970), and was maintained by 4-day passages in Minimum Essential Medium (MEM; GIBCO) supplemented by 10% calf serum. The modal chromosome number is 25 and the doubling time was approximately 15 hr.

Metabolic activation:

without

Test concentrations with justification for top dose:

up to 1.0 mg/ml

Vehicle / solvent:

Physiological saline

Controls

Untreated negative controls:

yes

Remarks:

untreated cells and solvent treated cells in which the incidence of aberrations was usually less than 3.0%.

Negative solvent / vehicle controls:

yes

Remarks:

ethanol

True negative controls:

no

Positive controls:

yes

Remarks:

A large number of substances were assayed in this study, including some

Positive control substance:

other: Test involved screening a large number of substances, some of which (eg hydrogen peroxide, sodium nitrite) gave positive results but no specific positive control as recommended in the guideline was used.

Details on test system and experimental conditions:

METHOD OF APPLICATION: Colcemid (final concen 0.2 ug(ml) was added to the culture 2 hr before cell harvesting, trypsinized and suspended in a hypotonic KCI solution (0.075 M) for 13 min at room temperature. The cells were centrifuged, fixed with acetic acid-methanol (I :3, v(v) and spread on clean glass slides, air-dried, and stained with Giemsa solution (1.5%, at pH 6.8; E. Merck) for 12-15 min.

DURATION
- Exposure duration: 24 and 48 h

NUMBER OF CELLS EVALUATED: A hundred well-spread metaphases were observed under the microscope (x 600 with a nocover objective lens).

OTHER EXAMINATIONS:
- Other: The incidence of polyploid cells as well as of cells with structural chromosomal aberrations such as chromatid or chromosome gaps, breaks, exchanges, ring formations, fragmentations and others, was recorded on each culture plate.

OTHER: The cells were exposed to each sample at three different doses

Evaluation criteria:

The results were considered to be negative if the incidence was less than 4.9%, equivocal if it was between 5.0 and 9.9%, and positive if it was more than 10.0%. Ethanol was used as the vehicle. For a quantitative evaluation of the clastogenic potential, the dose at which structural aberrations (including gaps) were detected in 20% of the metaphases was calculated (D20) along with the frequency of cells with exchange type aberrations per unit dose (mg/ml-TR value).  Low TR values indicate low carcinogenic potential in man. 

Results and discussion

Test results

Species / strain:

mammalian cell line, other: Chinese hamster lung fibroblasts

Metabolic activation:

without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

other: unclear from information available

Vehicle controls validity:

valid

Untreated negative controls validity:

other: a number of other substances known to be non mutagenic gave positive results in this study.

Any other information on results incl. tables

The results were negative at 48 hours. 1% of metaphases were polyploid and none showed structural abberations.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative without metabolic activation

Executive summary:

Chromosome aberrations were studied in Chinese Hamster lung fibroblasts exposed to sodium acetate in physiological saline by Japan's National Institute of Hygeinic Sciences. No metabolic activation was used. No evidence of cytogenicity was seen.