Neodecanoic acid, neodymium salt

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

other information

Rationale for reliability incl. deficiencies:

other: Non GLP screening study comparable to guideline study but only two strains of Salmonella typhimurium (TA98 and TA100) were used and the 2-Aminoanthracene positive control was the sole indicator of the efficacy of the S9-mix.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2000

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

only two strains of Salmonella typhimurium tested. 2-Aminoanthracene positive control was the sole indicator of the efficacy of the S9-mix.

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

neodymium(3+) 2-ethyl-2,5-dimethylhexanoic acid tris(2-ethyl-2,5-dimethylhexanoate)

EC Number:

600-768-2

Cas Number:

106726-11-8

Molecular formula:

C30H57NdO6

IUPAC Name:

neodymium(3+) 2-ethyl-2,5-dimethylhexanoic acid tris(2-ethyl-2,5-dimethylhexanoate)

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): Neodymium versatate
- Physical state: Blue powder
- Storage condition of test material: Ambient conditions

Method

Target gene:

Not applicable

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 100

Metabolic activation:

with and without

Metabolic activation system:

S9-mix

Test concentrations with justification for top dose:

61.7, 185, 556, 1670 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: ethanol
- Justification for choice of solvent/vehicle: no data

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

sterility control: plates were prepared to check the sterility of the test substance solutions and the S9 mix

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

2 µg/ plate; without metabolic activation; strain TA 98

Controls 2

Untreated negative controls:

yes

Remarks:

sterility control: plates were prepared to check the sterility of the test substance solutions and the S9 mix

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

1 µg/ plate; without metabolic activation; strain TA 100

Controls 3

Untreated negative controls:

yes

Remarks:

sterility control: plates were prepared to check the sterility of the test substance solutions and the S9 mix

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

1 µg/plate; with metabolic activation; strains TA 98 and TA 100

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 72h at 37°C


NUMBER OF REPLICATIONS: tested in duplicate

EVALUATION: After the period of incubation, the plates were scored by counting the number of revertant colonies on each plate, either manually, or using a calibrated Artek Model 890 Automatic colony counter

DETERMINATION OF CYTOTOXICITY
- Method: no data

Evaluation criteria:

The data sets for the tester strains TA 98 and TA 100 were judged positive if the increase in the mean revertants at the peak of the dose response is equal to or greater than two times the mean vehicle control value

Statistics:

For each replicate plating, the mean and standard error of the number of revertants per plate were calculated and reported

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

slight toxicity, indicated by thinning of the background lawn and reduction in revertant numbers, was observed at the highest dose-level, both in the absence and presence of S9 metabolism

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

slight toxicity, indicated by thinning of the background lawn and reduction in revertant numbers, was observed at the highest dose-level, both in the absence and presence of S9 metabolism

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

No further details

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative without metabolic activation
negative with metabolic activation

Under the conditions of this study, there is no indication that the test substance has mutagenic potential

Executive summary:

The ability of Neodymium Versatate test substance to induce gene mutations in Salmonella typhymurium was measured by examining the reversion of histidine auxotrophs to prototrophy.

 

Methods

The test item was tested in a single experiment, with and without a metabolic activation system, the S9 mix, prepared from a liver microsomal fraction (S9 fraction) of rats induced with phenobarbitone and betanaphthoflavone (Mixed Induction).

The experiment was performed according to the plate incorporation method. Two strains of bacteria Salmonella typhimurium: TA 98 an TA 100 were used. Each strain was exposed to five dose-levels of the test item (two plates/dose-level). After 72 hours of incubation at 37°C, the revertant colonies were scored.

 

The evaluation of the toxicity was performed on the basis of the observation of the decrease in the number of revertant colonies and/or a thinning of the bacterial lawn.

 

The test item Neodymium Versatate was dissolved in ethanol.

 

The dose-levels of the positive controls were as follows:

without S9 mix:

 - 2 μg/plate of 2 -Nitrofluorene: TA 98 strain

- 1 μg/plate of Sodium azide: TA 100 strain 

 

with S9 mix:

- 1 μg/plate of 2-Aminoanthracene: TA 98 and TA 100 strains

 

Results

The number of revertants for the vehicle and positive controls was as specified in the acceptance criteria. Sterility of the S9 mix and test substance solutions was confirmed by the absence of colonies on additional agar plates separately spread with these solutions. The study was therefore considered valid.

 

The selected treatment-levels both with and without S9 mix were:

- 61.7, 185, 556, 1670 and 5000 µg/plate, for the two tested strains

 

A slight toxicity was noted in highest dose-level with both strainTA98 and TA100, both in the absence and presence of S9 metabolic activation . The test item did not induce any noteworthy increase in the number of revertants, at any concentration, with any tester strain,in the absence or presence of S9 metabolic activation.

 

Conclusion

Under the experimental conditions, the test item Neodymium Versatate did not show any mutagenic potential in the bacterial reverse mutation test with Salmonella