Ammonium hydrogencarbonate

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

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 publication which meets basic scientific principles

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Micronucleus tests in mice on 39 food additives and eight miscellaneous chemicals

Author:

Hayashi M et al.

Year:

1988

Bibliographic source:

Fd. Chem. Toxic., 26, 487-500

Reference 2

Reference Type:

publication

Title:

SIDS Initial Assessment Report For SIAM 17

Author:

OECD

Year:

2006

Bibliographic source:

OECD SIDS AMMONIUM CHLORIDE

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)

Deviations:

yes

Remarks:

limited data

GLP compliance:

no

Type of assay:

micronucleus assay

Test material

Test material information

Constituent 1

Reference substance name:

Ammonium chloride

EC Number:

235-186-4

EC Name:

Ammonium chloride

Cas Number:

12125-02-9

IUPAC Name:

ammonium chloride

Details on test material:

- Name of test material (as cited in study report): Ammonium chloride
- Supplier: Japan Food Additive Association
- Analytical purity: purity 99.7%

Test animals

Species:

mouse

Strain:

other: ddY

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Shizuoka Agricultural Cooperative Association for Laboratory Animals, Shizu
- Age at study initiation: 8 weeks
- Diet (e.g. ad libitum): food pellets CE-2 (Japan Clea, Toky); ad libitum
- Water (e.g. ad libitum): water; ad libitum

Administration / exposure

Route of administration:

intraperitoneal

Vehicle:

- Vehicle(s)/solvent(s) used: saline

Duration of treatment / exposure:

24 h

Frequency of treatment:

Trial 1: one application
Trial 2: 4 injections every 24 h

Post exposure period:

24 h

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
62.5, 125, 250, 500 mg/kg bw
Basis:
nominal conc.
single injections

Doses / concentrations 2

Remarks:

Doses / Concentrations:
31.3, 62.5, 125, 250 mg/kg bw
Basis:
nominal conc.
four injections with 24-h intervals

No. of animals per sex per dose:

6

Control animals:

yes

Positive control(s):

mitomycin C;
- Route of administration: i.p.
- Doses / concentrations: 2.0 mg/kg bw

Examinations

Tissues and cell types examined:

bone marrow of femur

Details of tissue and slide preparation:

CRITERIA FOR DOSE SELECTION:
The maximum dose of NH4Cl was determined by pilot experiments using the multisampling at multi-dose levels method. Dose up to MTD (maximum tolerance dose)

DETAILS OF SLIDE PREPARATION:
Femoural marrow cells were flushed out with fetal bovine serum and fixed with methanol and stained with Giemsa.

METHOD OF ANALYSIS:
One thousand polychromatic erythrocytes per mouse were scored using a light microscope and the number of micronucleated erythrocytes (MNPCE) was recorded.

Evaluation criteria:

A positive result was recorded only when one or more treatment group(s) showed a statistically significant difference (P < 0.01) from the spontaneous level of MNPCEs and the trend test indicated a positive dose response (P < 0.05).

Statistics:

Data were compared with the binomial distribution specified by historical data from laboratory followed by Armitage trend test (Armitage, 1955)

Results and discussion

Test results

Sex:

male

Genotoxicity:

negative

Toxicity:

not specified

Vehicle controls validity:

valid

Negative controls validity:

not specified

Positive controls validity:

valid

Any other information on results incl. tables

Results:

Number of doses	Dose (mg/kg bw)	MNPCE (%)	PC (%)	Mortality
1	Saline	0.18 ± 0.18	56.8 ± 4.7	0/6
	62.5	0.12 ± 0.12	60.9 ± 4.2	0/6
	125	0.15 ± 0.14	61.7 ± 3.8	0/6
	250	0.13 ± 0.05	64.3 ± 2.5	0/6
	500	0.12 ± 0.08	56.9 ± 8.3	0/6
	2.0 MMC	4.18 ± 1.30*	52.3 ± 4.6	0/6
4	Saline	0.20 ± 0.09	59.9 ± 8.3	0/6
	31.3	0.25 ± 0.19	67.2 ± 13.5	0/6
	62.5	0.17 ± 0.10	63.7 ± 4.5	0/6
	125	0.20 ± 0.18	64.0 ± 9.2	0/6
	250	0.17 ± 0.08	61.6 ± 6.9	0/6
	2.0 MMC	7.15 ± 3.92*	32.2 ± 11.0	0/6

*: significantly different from the historical negative control : (P <0.01)

MNPCE: micronucleated polychromatic erythrocytes

PCE: polychromatic erythrocyt

MMC: Mitomycin C

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): negative