Registration Dossier

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

Referenceopen allclose all

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 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:
OECD Guideline 474 (Mammalian Erythrocyte Micronucleus Test)
Deviations:
yes
Remarks:
limited data
GLP compliance:
no
Type of assay:
micronucleus assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
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 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 / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
62.5, 125, 250, 500 mg/kg bw
Basis:
nominal conc.
single injections
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