Ammonium dihydrogen citrate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

no TA102 or WP2uvrA, no information of historical data.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Ammonium sulphate

EC Number:

231-984-1

EC Name:

Ammonium sulphate

Cas Number:

7783-20-2

Molecular formula:

H8N2O4S

IUPAC Name:

diammonium sulfate

Test material form:

solid

Details on test material:

Name of the substance: Ammoniumsulfat

Method

Target gene:

- S. typhimurium: Histidine gene

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

S9 fraction induced by Aroclor 1254

Test concentrations with justification for top dose:

Experiment 1 and 2 all 4 strains:
With and without S9-mix: 20, 100, 500, 2500, and 5000 μg/plate

Vehicle / solvent:

- Solvent used: aqua dest.
- Justification for choice of solvent: the substance was completely soluble in aqua dest.

Controls

Controls 1

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

9-aminoacridine

other: 5 μg N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) (dissolved in DMSO) for the strains TA 100 and TA 1535; 10 μg 4-nitro-o-phenylendiamine (dissolved in DMSO) for the strain TA 98

Remarks:

Without S9

Controls 2

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: 10 μg 2-aminoanthracene (dissolved in DMSO) for the strains TA 100, TA 98, TA 1537 and TA 1535

Remarks:

With S9

Details on test system and experimental conditions:

METHOD OF APPLICATION:in agar (plate incorporation); preincubation

DURATION
- Preincubation period: 20 minutes
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 3 replicates in both experiments.

NUMBER OF CELLS EVALUATED: 10^8 cells

DETERMINATION OF CYTOTOXICITY
- Method: Reduction in the number of spontaneous revertants or a clearing of the bacterial background lawn.

Evaluation criteria:

In general, a substance to be characterized as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results .

Statistics:

Not performed.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

but tested up to and including 5000 μg/plate.

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

but tested up to and including 5000 μg/plate.

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

but tested up to and including 5000 μg/plate.

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

but tested up to and including 5000 μg/plate.

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: No precipitation was observed up to and including 5000 μg/plate.

HISTORICAL CONTROL DATA: No data

ADDITIONAL INFORMATION ON CYTOTOXICITY:
- Measurement of cytotoxicity used: No toxicity was observed up to and including 5000 μg/plate.

Applicant's summary and conclusion

Conclusions:

The substance is not mutagenic in the Salmonella typhimurium reverse mutation assay performed according to OECD 471 guideline.

Executive summary:

The mutagenic activity of Ammonium sulphate was evaluated in accordance with OECD 471 guideline. The test was performed in two independent experiments, experiment 1 a plate incorporation test and experiment 2 a pre-incubation test using the Salmonella typhimurium strains TA 1535, TA 1537, TA 98 and TA 100. Dose levels up to and including 5000 μg/plate were tested in the absence and presence of S9-mix. Adequate positive controls and solvent controls were included.

No precipitation of the test item and no toxicity was observed up to and including the concentration of 5000 μg/plate.

No increase in revertant colony numbers of any of the four tester strains was observed following treatment with the substance at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). Based on the results, Ammonium sulphate is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.