Ammonium carbamate

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: Acceptable, well documented publication

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Primary Mutagenicity Screening of Food Additives Currently used in Japan

Author:

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

Year:

1984

Bibliographic source:

Fd. Chem. Toxic. 22: 623-636

Reference 2

Reference Type:

publication

Title:

SIDS Initial Assessment Report For SIAM 22

Author:

OECD

Year:

2006

Bibliographic source:

OECD SIDS Ammonium bicarbonate

Materials and methods

Principles of method if other than guideline:

acc. to Ishidate & Odashima (1977)
- Cells were exposed in the absence of metabolic acivation at three doses for 24 and 48 hr. Colcemid (final concn 0.2 μg/ml) was added to the cell culture 2 hours before cell harvesting. Staining was performed with Giemsa. 100 metaphases were observed under the microscope for structural chromosomal aberrations.

GLP compliance:

not specified

Type of assay:

in vitro mammalian chromosome aberration test

Test material

Test material information

Constituent 1

Reference substance name:

Ammonium hydrogencarbonate

EC Number:

213-911-5

EC Name:

Ammonium hydrogencarbonate

Cas Number:

1066-33-7

Molecular formula:

CH2O3.H3N

IUPAC Name:

ammonium hydrogen carbonate

Details on test material:

- Name of test material (as cited in study report): Ammonium bicarbonate
- Analytical purity: no data

Method

Species / strain

Species / strain / cell type:

other: Chinese hamster fibroblast cell line (CHL)

Details on mammalian cell type (if applicable):

- Source: The cell line was originally established from the lung of a newborn female hamster and was maintained by 4-day passages in Minimal Essential Medium supplemented by 10% calf serum. The modal chromosome number is 25 and the doubling time was approximately 15 hr.

Additional strain / cell type characteristics:

not specified

Metabolic activation:

without

Metabolic activation system:

none

Test concentrations with justification for top dose:

- up to 250 µg/ml

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: phosphate buffer

Controls

Untreated negative controls:

yes

Remarks:

(untreated cells)

Negative solvent / vehicle controls:

yes

Positive controls:

not specified

Positive control substance:

not specified

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium


DURATION
- Exposure duration: 48 h


SPINDLE INHIBITOR (cytogenetic assays): colcemid, 0.2 µg/ml
STAIN (for cytogenetic assays): Giemsa


NUMBER OF CELLS EVALUATED: 100

Evaluation criteria:

- The results were considered negative if the incidence of aberrations was less than 4.9%, equivocal if it was between 5.0 and 9.9%, and positive if it was more than 10.0%.
- When dose-response relationships were not found, additional experiments were carried out at similar dose levels.

Statistics:

- For a quantitative evaluation of the clastogenic potential of positive samples, the D20 (dose in mg/ml at which structural aberrations (including gaps) were detected in 20% of metaphases observed) was determined.
- Additionally, the TR value (indicates frequency of cells with exchange-type aberrations per unit dose (mg/ml)) was calculated.
- A high TR value exists for chemicals that show carcinogenic potential in animals.

Results and discussion

Test results

Species / strain:

other: CHL cells 1-164

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

not specified

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Results:

- Number of polyploid cells: 0%

- Number of structural aberrations: 2.0%

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative