Zirconium praseodymium yellow zircon

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:

no data given

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

GLP certificate missing.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

Only 2 bacterial strains were tested instead of 4.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Zirconium praseodymium yellow zircon

EC Number:

269-075-7

EC Name:

Zirconium praseodymium yellow zircon

Cas Number:

68187-15-5

Molecular formula:

Pr(x)Zr(1-x)SiO4 0,03≤x≤0,09

IUPAC Name:

silicon(4+) zirconium(4+) λ⁴-praseodymium(4+) dipraseodymium(3+) nonaoxidandiide

Test material form:

solid

Details on test material:

- Name: Sicocer F Gelb 2214
- EC Name: Zirconium Praseodymium Yellow Zircon
- Substance type: inorganic pigment
- Physical state: solid, yellow powder, odourless
- Storage condition of test material: at room temperature

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 98

Additional strain / cell type characteristics:

other: rfa; uvrB; ampicillin resistence (R factor plamid pKM 101); and a modified postreplication DNA repair system, which increases the mutation rate by inducing a defective repair in the DNA

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 100

Additional strain / cell type characteristics:

other: rfa; uvrB; ampicillin resistence (R factor plamid pKM 101); and a modified postreplication DNA repair system, which increases the mutation rate by inducing a defective repair in the DNA

Metabolic activation:

with and without

Metabolic activation system:

S9-mix

Test concentrations with justification for top dose:

0, 20, 100, 500, 2500 and 5000 µg/plate

Vehicle / solvent:

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

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Parallel with each experiment with and without S9-mix a solvent control is carried out.

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene (2.5 µg), dissolved in DMSO

Remarks:

with metabolic activation; strains TA 98 and TA 100

Controls 2

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Parallel with each experiment with and without S9-mix a solvent control is carried out.

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: N-methyl-N'-nitro-N-nitroso-guanidine (5 µg), dissolved in DMSO

Remarks:

without metabilic activation; strain TA 100

Controls 3

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

Parallel with each experiment with and without S9-mix a solvent control is carried out.

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylendiamine (10 µg), dissolved in DMSO

Remarks:

without metabolic activation; strain TA 98

Details on test system and experimental conditions:

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

DURATION
- Preincubation period: 20 minutes at 37°C
- Exposure duration: After incubation at 37°C for 48 hours in the dark, the bacterial colonies (his+ revertants) were counted.

NUMBER OF REPLICATIONS: 3 test plates per dose and test or 3 plates per control

DETERMINATION OF CYTOTOXICITY
- Method: Titer determination
In general, the titer is determined only in the experiments with S9-mix both without test substance (solvent only) and after adding the two highest amounts of substance.

Evaluation criteria:

In general, a substance to be characterised 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:

According to the OECD guideline a statistical analysis of the data is not mandatory.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

An increase in the number of his+ revertants was not observed both in the standard plate test and in the preincubation test either without S9-mix or after the addition of metabolic activation system.

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

No bacteriotoxic effect was observed.

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

An increase in the number of his+ revertants was not observed both in the standard plate test and in the preincubation test either without S9-mix or after the addition of metabolic activation system.

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

No bacteriotoxic effect was observed.

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

Solubility of the test substance: No precipitation of the test substance was found.

Applicant's summary and conclusion

Conclusions:

According to the results of the present study, the test substance Sicocer F Gelb 2214 is not mutagenic in the Ames test under the experimental conditions chosen here.