Ammonium iron(III) citrate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames assay:

The test chemical did not induce mutation in the Salmonella typhimurium strains both in the presence and absence of S9 metabolic activation system and hence is not likely to be mutagenic under the conditions of this study.

In vitro mammalian chromosome aberration study:

The test chemical did not induce chromosome aberrations in the mammalian cell line in the presence and absence of S9 metabolic activation system and hence it is not mutagenic in the chromosome aberration study performed.

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed publication.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

Gene mutation toxicity study was performed to determine the mutagenic nature of test chemical.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Target gene:

Histidine

Species / strain / cell type:

S. typhimurium, other: TA92, TA1535, TA100, TA1537, TA94 and TA98

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Cytokinesis block (if used):

No data

Metabolic activation:

with and without

Metabolic activation system:

Type and composition of metabolic activation system:
- source of S9 :liver microsome fraction
- method of preparation of S9 mix :The liver microsome fraction (S-9) was prepared from the liver of Fischer rats

Test concentrations with justification for top dose:

6 different concentrations were used; 100.0 mg/plate was the maximum concentration

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Phosphate buffer
- Justification for choice of solvent/vehicle: The test chemical was soluble in phosphate buffer

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

Remarks:

Phosphate buffer

True negative controls:

not specified

Positive controls:

not specified

Positive control substance:

not specified

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 mins
- Exposure duration: 48 hrs
- Expression time (cells in growth medium): 48 hrs
- Selection time (if incubation with a selection agent): No data
- Fixation time (start of exposure up to fixation or harvest of cells): No data

SELECTION AGENT (mutation assays): No data
SPINDLE INHIBITOR (cytogenetic assays): No data
STAIN (for cytogenetic assays): No data

NUMBER OF REPLICATIONS: Duplicate

NUMBER OF CELLS EVALUATED: No data

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data

OTHER EXAMINATIONS:
- Determination of polyploidy: No data
- Determination of endoreplication: No data
- Other: No data

OTHER: No data

Rationale for test conditions:

No data

Evaluation criteria:

The result was considered positive if the number of colonies found was twice the number in the control (exposed to the appropriate solvent or untreated).

Statistics:

No data

Key result

Species / strain:

S. typhimurium, other: TA92, TA1535, TA100, TA1537, TA94 and TA98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

not specified

Additional information on results:

ADDITIONAL INFORMATION ON CYTOTOXICITY: The maximum dose for negative results represents the highest non-cytotoxic dose used in the experiment

Remarks on result:

other: No mutagenic potential

Conclusions:

Test substance did not induce a doubling of revertant colonies over the control using S. typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98 in the presence and absence of S9 metabolic activation system and hence the chemical is not likely to classify as a gene mutant in vitro.

Executive summary:

Gene mutation toxicity study was performed to determine the mutagenic nature of test substance. The study was performed using S. typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98 with and without S9 metabolic activation system. The test was performed as per the preincubation assay at six different concentrations with 100.0 mg/plate being the maximum concentration. The chemical was dissolved in phosphate buffer. Preincubation was performed for 20 mins and the exposure duration was for 48 hrs. The result was considered positive if the number of colonies found was twice the number in the control (exposed to the appropriate solvent or untreated). Test substance did not induce a doubling of revertant colonies over the control using S. typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98 in the presence and absence of S9 metabolic activation system and hence the chemical is not likely to classify as a gene mutant in vitro.

Reference 2

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Data is from peer reviewed publication.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Principles of method if other than guideline:

Chromosomal aberration study was performed to determine the mutagenic nature of test chemical.

GLP compliance:

not specified

Type of assay:

other: Chromosome aberration assay

Target gene:

No data

Species / strain / cell type:

mammalian cell line, other: Chinese hamster fibroblast cell line CHL

Details on mammalian cell type (if applicable):

- Type and identity of media: Minimum
Essential Medium (MEM; GIBCO) supplemented by 10% calf serum
- Properly maintained: yes by 4 day passages
- Periodically checked for Mycoplasma contamination: No data available
- Periodically checked for karyotype stability: No data available
- Periodically "cleansed" against high spontaneous background: No data available

Additional strain / cell type characteristics:

not specified

Cytokinesis block (if used):

No data

Metabolic activation:

without

Metabolic activation system:

No data

Test concentrations with justification for top dose:

At three different doses with 0.25 mg/mL being the maximum dose concentration

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Physiological saline
- Justification for choice of solvent/vehicle: The chemical was soluble in Physiological saline

Untreated negative controls:

yes

Remarks:

Untreated cells served as negative control

Negative solvent / vehicle controls:

yes

Remarks:

Physiological saline

True negative controls:

not specified

Positive controls:

not specified

Positive control substance:

not specified

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium

DURATION
- Preincubation period: No data
- Exposure duration: 24 and 48 hrs
- Expression time (cells in growth medium): 24 and 48 hrs
- Selection time (if incubation with a selection agent): No data
- Fixation time (start of exposure up to fixation or harvest of cells): No data

SELECTION AGENT (mutation assays): Giemsa solution (1.5%, pH 6.8)
SPINDLE INHIBITOR (cytogenetic assays): Colcemid
STAIN (for cytogenetic assays): No data

NUMBER OF REPLICATIONS: No data

NUMBER OF CELLS EVALUATED: 100 well spread metaphases

DETERMINATION OF CYTOTOXICITY
- Method: mitotic index; cloning efficiency; relative total growth; other: No data

OTHER EXAMINATIONS:
- Determination of polyploidy: Yes
- Determination of endoreplication: No data
- Other: No data

OTHER: No data

Rationale for test conditions:

No data

Evaluation criteria:

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. 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%.

Statistics:

No data

Species / strain:

S. typhimurium, other: Chinese hamster fibroblast cell line CHL

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

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: No data
- Effects of osmolality: No data
- Evaporation from medium: No data
- Water solubility: No data
- Precipitation: No data
- Other confounding effects: No data

RANGE-FINDING/SCREENING STUDIES: The maximum dose of each sample was selected
by a preliminary test in which the dose needed
for 50% cell-growth inhibition was estimated using a cell densitometer

COMPARISON WITH HISTORICAL CONTROL DATA: No data

ADDITIONAL INFORMATION ON CYTOTOXICITY: No data

Remarks on result:

other: No mutagenic potential

Table: Mutagenicity of the test chemical in chromosomal aberration test in vitro

Max dose	Solvent	Polyploid (%)	Structural aberrations		Result
			%	hr
0.25	Physiological saline	1.0	3.0	24	-

Conclusions:

Test chemical did not induce chromosomal aberration in Chinese hamster fibroblast cell line CHL and hence it is not likely to classify as a gene mutant in vitro.

Executive summary:

Chromosomal aberration study was performed to determine the mutagenic nature of test chemical. The cells were exposed to the test material at three different doses with 0.25 mg/mL being the maximum concentration for 24hr and 48 hrs. Colcemid (final concn 0.2µg/ml) was added to the culture 2 hr before cell harvesting. The cells were then trypsinized and suspended in a hypotonic KCI solution (0.075 M) for 13 min at room temperature. After centrifugation the cells were fixed with acetic acid-methanol (1:3, v/v) and spread on clean glass slides. After air-drying, the slides were stained with Giemsa solution for 12-15 min. A hundred well-spread metaphases were observed under the microscope. In the present studies, no metabolic activation systems were applied. 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. Untreated cells and solvent-treated cells served as negative controls, in which the incidence of aberrations was usually less than 3.0%. 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%. Test chemical did not induce chromosomal aberration in Chinese hamster fibroblast cell line CHL and hence it is not likely to classify as a gene mutant in vitro.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Gene mutation in vitro:

Data available from various sources was reviewed to determine the mutagenic nature of the given test chemical. The studies are as mentioned below:

Ames assay:

In different studies, the given test chemical has been investigated for the mutagenic nature. The studies are as mentioned below:

 

Gene mutation toxicity study was performed to determine the mutagenic nature of test substance. The study was performed using S. typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98 with and without S9 metabolic activation system. The test was performed as per the preincubation assay at six different concentrations with 100.0 mg/plate being the maximum concentration. The chemical was dissolved in phosphate buffer. Preincubation was performed for 20 mins and the exposure duration was for 48 hrs. The result was considered positive if the number of colonies found was twice the number in the control (exposed to the appropriate solvent or untreated). Test substance did not induce a doubling of revertant colonies over the control using S. typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98 in the presence and absence of S9 metabolic activation system and hence the chemical is not likely to classify as a gene mutant in vitro.

Thus, based on the above summarized studies on test chemical, it can be concluded that the given test chemical did not induce mutation in the Salmonella typhimurium strains both in the presence and absence of S9 metabolic activation system and hence is not likely to be mutagenic under the conditions of this study.

 

In vitro mammalian chromosome aberration study:

In different studies, the given test chemical has been investigated for the mutagenic nature. The studies are as mentioned below:

Chromosomal aberration study was performed to determine the mutagenic nature of test chemical. The cells were exposed to the test material at three different doses with 0.25 mg/mL being the maximum concentration for 24hr and 48 hrs. Colcemid (final concn 0.2µg/ml) was added to the culture 2 hr before cell harvesting. The cells were then trypsinized and suspended in a hypotonic KCI solution (0.075 M) for 13 min at room temperature. After centrifugation the cells were fixed with acetic acid-methanol (1:3, v/v) and spread on clean glass slides. After air-drying, the slides were stained with Giemsa solution for 12-15 min. A hundred well-spread metaphases were observed under the microscope. In the present studies, no metabolic activation systems were applied. 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. Untreated cells and solvent-treated cells served as negative controls, in which the incidence of aberrations was usually less than 3.0%. 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%. Test chemical did not induce chromosomal aberration in Chinese hamster fibroblast cell line CHL and hence it is not likely to classify as a gene mutant in vitro.

 

In another in vitro mammalian chromosome aberration test was performed for the given test chemical using Chinese hamster fibroblast cell line CHL. The cells were exposed to the test material at 1.0 mg/ml for 48 hr. No metabolic activation systems were applied. 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. Untreated cells and solvent-treated cells served as negative controls, in which the incidence of aberrations was usually less than 3.0%. 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%. The given test chemical does not induce chromosomal aberrations in the Chinese hamster fibroblast cell line and hence is negative for gene mutation in vitro.

Thus, based on the above summarized studies on test chemical, it can be concluded that the given test chemical did not induce chromosome aberrations in the mammalian cell line in the presence and absence of S9 metabolic activation system and hence it is not mutagenic in the chromosome aberration study performed.

Justification for classification or non-classification

Based on the data available and applying weight of evidence approach, the given test chemical does not exhibit gene mutation in vitro by Ames assay and In vitro mammalian chromosome aberration study. Hence, the test chemical is not likely to classify as a gene mutant as per the criteria mentioned in CLP regulation.