Silsesquioxanes, 3-phosphonopropyl, Et Me esters, sodium salts

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:

key study

Study period:

2008-03-03 to 2008-05-19

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD Guideline under GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Silicophosphonat

IUPAC Name:

Silicophosphonat

Details on test material:

Name of test substance: Silicophosphonat
Test substance No.: 08/0014-1
Batch identification: Partie 21/05
Purity/composition: 39% of the main component in water
Homogeneity: The homogeneity of the test substance was guaranteed, by mixing before preparation of the test substance preparations.
Storage stability: The stability of the test substance under storage conditions throughout the study period is guaranteed as indicated by the manufacturer, and the manufacturer holds this responsibility.
Date of production: 2005
Physical state, appearance: Liquid, colorless, clear
Storage conditions: Room temperature

Method

Target gene:

strain specific

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:

Leberhomogenat (S9-Mix)

Test concentrations with justification for top dose:

1st Experiment
Strains: TA 1535, TA 100, TA 1537, TA 98, E. coli WP2 uvrA
Doses: 0; 60; 300; 1 500; 7 500 and 15 000 μg/plate
Type of test: Standard plate test with and without S9 mix
Number of plates: 3 test plates per dose or per control
2nd Experiment
Strains: TA 1535, TA 100, TA 1537, TA 98, E. coli WP2 uvrA
Doses: 0; 937.5; 1 875; 3 750; 7 500 and 15 000 μg/plate
Type of test: Preincubation test with and without S9 mix
Number of plates: 3 test plates per dose or per control

Vehicle / solvent:

Solvent: water

Details on test system and experimental conditions:

METHOD OF APPLICATION:
- Standard plate test and preincubation test

DURATION
- Exposure duration: 48 h -72h

NUMBER OF REPLICATES:
- Three replicates for each concentration/test compound

DETERMINATION OF CYTOTOXICITY
Toxicity detected by a
• decrease in the number of revertants
• clearing or diminution of the background lawn (= reduced his- or trp- background growth)
• reduction in the titer
is recorded for all test groups both with and without S9 mix in all experiments and indicated in
the tables.

Evaluation criteria:

Acceptance criteria
Generally, the experiment is considered valid if the following criteria are met:
• The number of revertant colonies in the negative controls was within the range of the
historical negative control data for each tester strain (see Appendix 5).
• The sterility controls revealed no indication of bacterial contamination.
• The positive control substances both with and without S9 mix induced a distinct increase in
the number of revertant colonies within the range of the historical positive control data or
above (see Appendix 6).
• The titer of viable bacteria was > 108/mL.

Assessment criteria
The test chemical is considered positive in this assay if the following criteria are met:
• A dose-related and reproducible increase in the number of revertant colonies, i.e. about
doubling of the spontaneous mutation rate in at least one tester strain either without
S9 mix or after adding a metabolizing system.
A test substance is generally considered non-mutagenic in this test if:
• The number of revertants for all tester strains were within the historical negative control
range under all experimental conditions in at least two experiments carried out
independently of each other.

Statistics:

-

Results and discussion

Test results

Test results 1

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

in the preincubation and the standard plate test

Cytotoxicity / choice of top concentrations:

other: only in the preincubation test at 15000µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

in the preincubation and the standard plate test

Cytotoxicity / choice of top concentrations:

other: only in the preincubation test at 15000µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TOXICITY
No clear bacteriotoxic effect (reduced his- or trp- background growth, decrease in the number
of his+ or trp+ revertants) was observed in the standard plate test. However, in all tester
strains the titer was reduced in at least the top dose applied.
In the preincubation assay bacteriotoxicity (reduced his- or trp- background growth, decrease
in the number of his+ or trp+ revertants, reduction in the titer) was observed at
15 000 μg/plate.

SOLUBILITY
No test substance precipitation was found with and without S9 mix.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with metabolic activation in the preincubation and the standard plate test
negative without metabolic activation in the preincubation and the standard plate test

Thus, under the experimental conditions chosen, it is concluded that Silicophosphonat
is not a mutagenic substance in the bacterial reverse mutation test in the absence and the
presence of metabolic activation.

Executive summary:

According to the results of the present study, Silicophosphonat did not lead to an increase in the number of revertant colonies either without S9 mix or after adding a metabolizing system in two experiments carried out independently of each other (standard plate test and preincubation assay). Besides, the results of the negative as well as the positive controls performed in parallel corroborated the validity of this study, since the values fulfilled the acceptance criteria of this study. In this study with and without S9 mix, the number of revertant colonies in the negative controls was within the range of the historical negative control data for each tester strain. In addition, the positive control substances both with and without S9 mix induced a significant increase in the number of revertant