Aluminium cerium lutetium oxide

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:

July 26, 2016 - August 04, 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1997

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Version / remarks:

2008

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Japanese guidelines for mutagenicity testing. Environmental and Molecular Mutagenesis 21: 2-7

Version / remarks:

1993

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

aluminium cerium lutetium oxide

EC Number:

942-299-9

Cas Number:

1279099-21-6

Molecular formula:

Lu2.8-2.99Ce0.01-0.2Al5O12

IUPAC Name:

aluminium cerium lutetium oxide

Test material form:

solid

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

liver S9 mix frorn Aroclor 1254-pretreated rats

Test concentrations with justification for top dose:

First experiment: 5, 15.8, 50, 158, 500, 1580, 5000 µg/plate (+/- S9 mix)
Second experiment: 50, 158, 500, 1580, 5000 µg/plate (+/- S9 mix)

A maximum concentration of 5000 μg/plate was selected, in order that initial treatments were performed up to the maximum recommended concentration according to current regulatory guidelines (OECD, 1997).

Vehicle / solvent:

- Vehicle/solvent used: DMSO
- Justification for choice of solvent/vehicle: Based on preliminary data, the test item showed best solubility performance in DMSO.

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

sodium azide

other: Daunomycin, 2-Aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION:in agar (plate incorporation)

DURATION
- Exposure duration: 2-3 days

NUMBER OF REPLICATIONS: 3

Evaluation criteria:

A test material was to be defined as negative or non-mutagenic in this assay if
• the assay was to be considered valid, and
• "no" or "weak increases" occurred in the test series performed ("weak increases" randomly occur due to experimental variation)

For valid data, the test material was considered to be positive or mutagenic if:
• a dose dependent (over at least two test material concentrations) increase in the number of revertants was induced, the maximal effect was a "clear increase", and the effects were reproduced at similar concentration levels in the same test system, or
• "clear increases" occurred at least at one test material concentration, higher concentrations showed strong precipitation or cytotoxicity, and the effects were reproduced at the same concentration level in the same test system.

In general, two series of experiments must be performed. However, there is no requirement for verification of a clear positive response (OECD TG 471, 1997).
Results which only partially satisfied the above criteria were dealt with on a case-by-case basis. Biological relevance was taken into account, for example consistency of response within and between concentrations and (where applicable) between experiments.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Solubility: Due to the limited solubility of the test material, suspensions were used between 50 and 5000 μg/plate.
- Precipitation: >= 1580 µg/plate

RANGE-FINDING/SCREENING STUDIES: The first experiment was used as range-finding study.

Applicant's summary and conclusion

Conclusions:

lt was concluded that with and without addition of S9 mix as the external metabolizing system, the test item was not mutagenic under the experimental conditions described.

Executive summary:

The present study was conducted to investigate the test material for mutagenic potential in a bacterial reverse gene mutation assay in the absence and in the presence of a rat liver metabolizing system (S9 mix).

The investigations for the mutagenic potential of the test item were performed using Salmonella typhimurium tester strains TA 98, TA 100, TA 1535 and TA 1537, and Escherichia coli WP2 uvrA. The plate incorporation test with and without addition of liver S9 mix from Aroclor 1254-pretreated rats was used. In this study, two experimental series were performed. In the two series with S9 mix, 10 % S9 mix were used in the 1st and 30% S9 in the 2nd series, respectively.

Vehicle and positive control treatments were included for all strains. The mean numbers of revertant colonies all feel within acceptable ranges for vehicle control treatments, and were clearly elevated by positive control treatments, thus, showing the expected reversion properties of all strains and good metabolic activity of the S9 mix used.

Following the test item treatments of all the tester strains in the absence and presence of S9 mix, no relevant increases in revertant numbers were observed.