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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2012-05-02 to 2012-05-11
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-Guidance study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Qualifier:
according to
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
GLP compliance:
yes (incl. certificate)
Remarks:
Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht, Kaiser-Friedrich-Straße 7, 55116 Mainz
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
other: solid
Details on test material:
- Name of test material (as cited in study report): Samarium oxide
- Molecular formula (if other than submission substance): Sm2O3
- Molecular weight (if other than submission substance): not stated
- Analytical purity: > 99,9%
- Lot/batch No.: 228672
- Expiration date of the lot/batch: March 2015
- Stability under test conditions: not stated
- Storage condition of test material: The test item was stored in a closed vessel dry at room temperature: (20 +- 5°C).

Method

Target gene:
his operone
Species / strain
Species / strain:
other: TA 97a, TA 98, TA 100, TA 102, TA 1535
Metabolic activation:
with and without
Metabolic activation system:
Liver S-9 Fraction of Aroclor 1254-induced male Sprague-Dawley rats. Batch No: 2861 Trinova Biochem. Gießen.
Test concentrations with justification for top dose:
TA 97a, TA 98, TA 100, TA 102 and TA 1535 (first experiment):
Four plates with and four plates without S9 mix were used per strain and dose.
without and with activation: 0, 51, 157, 498, 1497 and 5007 µg/plate;
Plate incorporation method.

TA 97a, TA 98, TA 100, TA 102 and TA 1535 (second experiment):
317, 626, 1255, 2508 and 5011 µg/plate
Pre-incubation method.
Vehicle:
water
Controls
Negative controls:
yes
Solvent controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
sodium azide
benzo(a)pyrene
other: 4-Nitro-1,2-phenylene diamine and 2-Amino-anthracene
Details on test system and conditions:
METHOD OF APPLICATION:
- Plate incorporation method (first experiment)
- preincubation (second experiment)


DURATION
- Preincubation period: 20 min.
- Temperature: 37°C
- Exposure duration: 2 days

NUMBER OF REPLICATIONS: 4

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth
Evaluation criteria:
The colonies were counted visually, the numbers were recorded. A spreadsheet software (Microsoft Excel (R)) was used to calculate mean values and standard deviations of each treatment, solvent control and positive control. The increase factor f(I) of revertant induction (mean revertants divided by mean spontaneous revertants) were also calculated.
A test item is considered to have mutagenic potential, if a significant, reproducible increase of revertant colonies per plate (increase factor >=2) in at least one strain can be observed. A concentration-related increase over the range tested can also be taken as a sign of mutagenic activity.

Results and discussion

Test results
Species / strain:
other: TA 97a, TA 98, TA 100, TA 102, TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
no
Vehicle controls valid:
yes
Negative controls valid:
not examined
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

First Experiment:

The mean revertant values of the four replicates are presented in the following table. Concentrations of the test item are stated as nominal concentrations, as suspensions had to be tested due to the poor solubility of the test item. As no complete dissolution was possible, undissolved particles were visible on the plates.

Strain     TA97a    TA98    TA100    TA102    TA1535  
Induction    -S9  +S9  -S9  +S9  -S9  +S9  -S9  +S9  -S9  +S9
 H2O  Mean 108 116 15 16 87 89 140 146 13 15
   sd 13.1 5.1 3.9 1.4 10.2 3.6 7.9 7.7 1.5 2.6
 DMSO  Mean 104 108 12 17 88 91 150 149 15 17
   sd 6.5 13.1 1.7 1.2 6.8 11.4 14.7 10.2 1.7 1.0
Positive Controls Mean  531 583 245 217 516 559 582 632 212 202
   sd 74 88 15 15 38 28 25 39 21 21
   f(I) 5.11 5.40 20.42 12.76 5.93 6.14 3.88 4.24 16.31 11.88
5007 µg/pl.  Mean 113 118 17 15 79 77 152 144 15 15
   sd 6 4 2 1 6 10 6 9 4  1
   f(I) 1.05 1.02 1.13 0.94 0.91 0.87 1.09 0.99 1.15 1.00
1497 µg/pl.  Mean 117 119 16 15 84 93 145 142 17  15
   sd 3 5 2 1 11 13 10 9 4  2
   f(I) 1.08 1.03 1.07 0.94 0.97 1.04 1.04 0.97 1.31  1.00
498 µg/pl.  Mean 120 121 16 16 77 96 148 137 16 16
   sd 2 2 2  1 8 9 5 6 3 2
   f(I) 1.11 1.04 1.07 1.00 0.89 1.08 1.06 0.94 1.23 1.07
157 µg/pl.  Mean 114 116 16 15 76 93 129 147 15 14
   sd 3 4 2 2 22 16 10 13 4 1
   f(I) 1.06 1.00 1.07 0.94 0.87 1.04 0.92 1.01 1.15 0.93
51 µg/pl.  Mean 120 113 15 16 82 84 144 133 14 14
   sd 3 5 4 1 5 6 8 12 3 1
   f(I) 1.11 0.97 1.00 1.00 0.94 0.94 1.03 0.91 1.08 0.93

Second Experiment:

The mean revertant values of the four replicates are presented in the following table. Concentrations of the test item are stated as nominal concentrations, as suspensions had to be tested due to the poor solubility of the test item. As no complete dissolution was possible, undissolved particles were visible on the plates.

Strain     TA97a    TA98    TA100    TA102    TA1535  
Induction    -S9  +S9  -S9  +S9  -S9  +S9  -S9  +S9  -S9  +S9
 H2O  Mean 116 106 21 20 66 83 135 137 14 14
   sd 15.9 7.5 2.5 2.3 4.3 12.0 18.3 18.2 1.3 3.0
 DMSO  Mean 112 109 15 18 70 84 138 146 14 13
   sd 3.0 6.7 2.6 2.9 9.7 5.7 9.2 4.5 2.2 3.4
Positive Controls Mean  449 301 885 824 683 617 593 692 343 232
   sd 75 38 47 53 82 98 36 67 80 8
   f(I) 4.01 2.76 59.00 45.78 10.35 7.35 4.30 4.74 24.50 17.85
5011 µg/pl.  Mean 101 103 16 17 114 102 138 134 15 16
   sd 7 7 2 4 6 7 3 15 2  2
   f(I) 0.87 0.97 0.76 0.85 1.73 1.23 1.02 0.98 1.07 1.14
2508 µg/pl.  Mean 102 101 15 19 92 100 132 141 15 16
   sd 5 12 2 2 19 4 5 2 1  3
   f(I) 0.88 0.95 0.71 0.95 1.39 1.20 0.98 1.03 1.07  1.14
1255 µg/pl.  Mean 112 96 13 18 85 100 151 146 14 14
   sd 8 4 3 2 10 7 7 9 1 3
   f(I) 0.97 0.91 0.62 0.90 1.29 1.20 1.12 1.07 1.00 1.00
626 µg/pl.  Mean 93 98 15 14 87 96 151 129 16 14
   sd 3 6 1 2 6 8 8 4 2 3
   f(I) 0.80 0.92 0.71 0.70 1.32 1.16 1.12 0.94 1.14 1.00
317 µg/pl.  Mean 97 93 15 14 84 105 136 145 16 14
   sd 4 3 2 3 11 9 6 10 2 1
   f(I) 0.84 0.88 0.71 0.70 1.27 1.27 1.01 1.06 1.14 1.00

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with and without metaboic activation
Executive summary:

The test item didn't show mutagenic effects in both experiments. The number of revertant colonies was not increased in comparison with the spontaneous revertants (solvent only). Cytotoxicity of the test item was not detected. The background lawn was visible and the number of revertants was not significantly decreased.

As no complete dissolution was possible, undissolved particles were visible on the plates.

Therefore it can be stated, that under the test conditions, the test item Samarium oxide is not mutagenic in the Bacterial Reverse Mutation Test using Salmonella typhimurium, strains TA 97a, TA 98, TA 100, TA 102 and TA 1535.