Ammonium iron bis(sulphate)

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

In aqueous solution ammonium iron bis(sulphate) dissociates forming sulfate, ammonium and ferric ions. The genetic toxicity of this substance can therefore be assessed by evaluating the genetic toxicity of substances forming the same ions upon dissolution. In vitro gene mutation studies on ammonium chloride, ammonium hydrogencarbonate, ferric chloride, ferric ammonium citrate and ferrous sulfate reported non-mutagenic properties for all these substances both, with an without metabolic activation. Therefore, ammonium iron bis(sulphate) is expected to be non-mutagenic, as well.

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:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

Reverse mutation assays using S. typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98 were carried out according to the method of Ames, McCann & Yamasaki (1975).

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

Purity: 99.7 %. Samples were supplied from the Japan Food Additives Association, Tokyo, at the request of the Ministry of Health and Welfare of Japan, where the purity and quality of each sample were checked.

Target gene:

his

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix prepared from the liver of Fischer rats pretreated with polychlorinated biphenyls

Test concentrations with justification for top dose:

six different concentrations, maximum dose: 10 mg/plate

Vehicle / solvent:

phosphate buffer

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

no

Details on test system and experimental conditions:

Cells cultured overnight were pre-incubated with both the test sample and the S-9 mix for 20 min at 37°C before plating. Duplicate plates were used for each of six different concentrations of the sample. The number of revertant (his +) colonies was scored after incubation at 37°C for 2 days.

Evaluation criteria:

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

Species / strain:

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

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

Conclusions:

Ammonium chloride was not mutagenic in an Ames test with and without metabolic activation.

Executive summary:

In this publication by Ishidate Jr et al. (published in 1984) the mutagenicity of broad variety of substances used as food additives is evaluated. A bacterial reverse mutation assay is used to investigate the mutagenicity of ammonium chloride. Six test strains were used in the experiments and each was conducted with and without metabolic activation. The results of all tests were negative.

Reference 2

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:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

Reverse mutation assays using S. typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98 were carried out according to the method of Ames, McCann & Yamasaki (1975).

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

Samples were supplied from the Japan Food Additives Association, Tokyo, at the request of the Ministry of Health and Welfare of Japan, where the purity and quality of each sample were checked.

Target gene:

his

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix prepared from the liver of Fischer rats pretreated with polychlorinated biphenyls

Test concentrations with justification for top dose:

Six different concentrations, maximum dose: 25 mg/plate

Vehicle / solvent:

phosphate buffer

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

no

Details on test system and experimental conditions:

Cells cultured overnight were pre-incubated with both the test sample and the S-9 mix for 20 min at 37°C before plating. Duplicate plates were used for each of six different concentrations of the sample. The number of revertant (his +) colonies was scored after incubation at 37°C for 2 days.

Evaluation criteria:

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

Species / strain:

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

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

Conclusions:

Ammonium hydrogencarbonate was not mutagenic in an Ames test with and without metabolic activation.

Executive summary:

In this publication by Ishidate Jr et al. (published in 1984) the mutagenicity of broad variety of substances used as food additives is evaluated. A bacterial reverse mutation assay is used to investigate the mutagenicity of ammonium hydrogencarbonate. Six test strains were used in the experiments and each was conducted with and without metabolic activation. The results of all tests were negative.

Reference 3

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:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

Reverse mutation assays using S. typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98 were carried out according to the method of Ames, McCann & Yamasaki (1975).

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

Samples were supplied from the Japan Food Additives Association, Tokyo, at the request of the Ministry of Health and Welfare of Japan, where the purity and quality of each sample were checked.

Target gene:

his

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix prepared from the liver of Fischer rats pretreated with polychlorinated biphenyls

Test concentrations with justification for top dose:

six different concentrations, maximum dose: 100 mg/plate

Vehicle / solvent:

phosphate buffer

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

no

Details on test system and experimental conditions:

Cells cultured overnight were pre-incubated with both the test sample and the S-9 mix for 20 min at 37°C before plating. Duplicate plates were used for each of six different concentrations of the sample. The number of revertant (his +) colonies was scored after incubation at 37°C for 2 days.

Evaluation criteria:

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

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Conclusions:

Ferric ammonium citrate was not mutagenic in an Ames test with and without metabolic activation.

Executive summary:

In this publication by Ishidate Jr et al. (published in 1984) the mutagenicity of broad variety of substances used as food additives is evaluated. A bacterial reverse mutation assay is used to investigate the mutagenicity of ferric ammonium citrate. Six test strains were used in the experiments and each was conducted with and without metabolic activation. The results of all tests were negative.

Reference 4

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:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

The experimental materials, methods, and procedures as explained below are based on those described by Ames et al., 1975, Mutat Res 31:347–364.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

Supplier: Mallinckrodt. Purity: 100%. The compound was acquired by FDA, NCI, and the NCI Chemical Carcinogen References Standards Repository (Midwest Research Institute [MRI], Kansas City, MO) and supplied as coded samples to the contract laboratory (Bio Reliance Corp., Rockville, MD).

Species / strain / cell type:

S. typhimurium, other: TA97a, TA98, TA100, TA102, TA1535, TA1537, TA1538

Metabolic activation:

with and without

Metabolic activation system:

S9 mix: 8 mM MgCl2, 33 mM KCl, 5 mM glucose-6-phosphate, 4 mM NADP, 100 mM sodium phosphate (pH 7.4), appropriate S9 homogenate (rat/hamster) at a concentration of 0.1 ml/ml of mix.

Test concentrations with justification for top dose:

The doses to be tested in the mutagenicity assay were selected based on the levels of cytotoxicity observed in a preliminary dose range-finding study using strain TA100. Ten dose levels of the chemical, one plate per dose, were tested both in the presence and absence of induced hamster S9. If no toxicity was observed, a total maximum dose of 10 mg of test chemical per plate was used.

Vehicle / solvent:

10% water, 1% dimethyl sulfoxide (DMSO), and 1N HCl

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

not specified

Details on test system and experimental conditions:

Plate Incorporation Methodology. For testing in the absence of S9 mix, 100 ml of the tester strain and 50 ml of solvent or test chemical were added to 2.5 ml of molten selective top agar at 45 °C. When S9 was used, 0.5 ml of S9 mix, 100 ml of tester strain, and 50 ml of solvent or test chemical were added to 2.0 ml of molten selective top agar at 45 °C. The plates were incubated for 48 hr at 37 °C. Preincubation Methodology. In the test with metabolic activation, 500 ml of S9 mix was added to glass culture tubes preheated to 37 °C. To these tubes were added 100 ml of the appropriate tester strain and 50 ml of vehicle or the appropriate concentration of test article. When the chemical was tested without metabolic activation, 500 ml of the cofactor mix without S9 was substituted for the complete S9 mix. After vortexing, the mixture was incubated for 20 min at 37 °C. Top agar (2 ml) was then added to each tube and the mixture was overlaid onto 25 ml of minimal bottom agar. After the overlay had solidified, the plates were inverted and incubated for approximately 48 hr at 37 °C. All plates were counted with a Mini Count automated colony counter (Imaging Products, International, Inc., Chantilly, VA), which was calibrated prior to use.

Evaluation criteria:

The criteria used to evaluate a test stipulated that a test article must induce at least a doubling (TA97a, TA98, TA100, TA102, and TA1535) in the mean number of revertant per plate of at least one tester strain for it to be considered positive. This increase in the mean revertants per plate must be accompanied by a dose response to increasing concentrations of the test chemical. If the study shows a dose–response, but with a less than 3-fold increase on TA1537 or TA1538, the response must be confirmed in a repeat experiment.

Species / strain:

S. typhimurium, other: TA97a, TA98, TA100, TA102, TA1535, TA1537, TA1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not determined

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Conclusions:

There was no evidence of a mutagenic response with iron (III) chloride in this bacterial reverse mutation assay with and without metabolic activation.

Executive summary:

In this publication by Dunkel et al. 1999 the genotoxicity of several iron compounds is evaluated. A bacterial reverse mutation assay is used to investigate the mutagenicity of iron (III) chloride. Seven test strains were used in the experiments and each was conducted with and without metabolic activation. The results of all tests were negative. The validity of the experiments was demonstrated by positive reactions induced by reference mutagens.

Reference 5

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

Reverse mutation assays using S. typhimurium strains TA92, TA1535, TA100, TA1537, TA94 and TA98 were carried out according to the method of Ames, McCann & Yamasaki (1975).

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

Purity: 85 %. Samples were supplied from the Japan Food Additives Association, Tokyo, at the request of the Ministry of Health and Welfare of Japan, where the purity and quality of each sample were checked.

Target gene:

his

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S-9 mix prepared from the liver of Fischer rats pretreated with polychlorinated biphenyls

Test concentrations with justification for top dose:

six different concentrations, maximum dose: 10 mg/plate

Vehicle / solvent:

phosphate buffer

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

no

Details on test system and experimental conditions:

Cells cultured overnight were pre-incubated with both the test sample and the S-9 mix for 20 min at 37°C before plating. Duplicate plates were used for each of six different concentrations of the sample. The number of revertant (his +) colonies was scored after incubation at 37°C for 2 days.

Evaluation criteria:

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

Species / strain:

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

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

Conclusions:

Iron(II) sulfate was not mutagenic in an Ames test with and without metabolic activation.

Executive summary:

In this publication by Ishidate Jr et al. (published in 1984) the mutagenicity of broad variety of substances used as food additives is evaluated. A bacterial reverse mutation assay is used to investigate the mutagenicity of iron(II) sulfate. Six test strains were used in the experiments and each was conducted with and without metabolic activation. The results of all tests were negative.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Justification for classification or non-classification

In aqueous solution ammonium iron bis(sulphate) dissociates forming sulfate, ammonium and ferric ions. The genetic toxicity of this substance can therefore be assessed by evaluating the genetic toxicity of substances forming the same ions upon dissolution. In vitro gene mutation studies on ammonium chloride, ammonium hydrogencarbonate, ferric chloride, ferric ammonium citrate and ferrous sulfate reported non-mutagenic properties for all these substances both, with an without metabolic activation. Therefore, ammonium iron bis(sulphate) is expected to be non-mutagenic, as well.