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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Study plane dated 22. March 2019; Experimental starting date 9. April 2019; Experimental completion date 18. April 2019; Final Report 21 May 2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
OECD 471

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2019
Report date:
2019

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
adopted 21. Jul. 1997
Deviations:
no
Principles of method if other than guideline:
Cited from OECD guideline 471:
“The bacterial reverse mutation test uses amino-acid requiring strains of Salmonella typhi-murium to detect point mutations, which involve substitution, addition or deletion of one or a few DNA base pairs. The principle of this bacterial reverse mutation test is that it detects mutations which revert mutations present in the test strains and restore the functional capa-bility of the bacteria to synthesize an essential amino acid.”
The bacterial reverse mutation test is commonly employed as an initial screen for genotoxic activity and, in particular, for point mutation-inducing activity.
Principle of the test method: Suspensions of bacterial cells are exposed to the test sub-stance in the presence and in the absence of an exogenous metabolic activation system. In the plate incorporation method, these suspensions are mixed with an overlay agar and plated immediately onto minimal medium. In the pre-incubation method, the treatment mix-ture is incubated and then mixed with an overlay agar before plating onto minimal medium. For both techniques, after 2 days of incubation, revertant colonies are counted and com-pared to the number of spontaneous revertant colonies on solvent control plates.
This study was performed in order to evaluate the mutagenic potential of Sodium phenylphosphinate in the Bacterial Reverse Mutation Test using five strains of Salmonella typhimurium.
GLP compliance:
yes (incl. QA statement)
Remarks:
Copy of GLP certificate is atteched in the Final Report of study " Statement of GLP compliance"
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Sodium phenylphosphinate
EC Number:
224-305-5
EC Name:
Sodium phenylphosphinate
Cas Number:
4297-95-4
Molecular formula:
C6H7O2P.Na
IUPAC Name:
sodium phenylphosphinate
Test material form:
solid: particulate/powder
Specific details on test material used for the study:
The test item Sodium phenylphosphinate was tested in the Salmonella typhimurium re-verse mutation assay with five strains of Salmonella typhimurium (TA97a, TA98, TA100, TA102 and TA1535).
The test was performed in two experiments in the presence and absence of metabolic activation, with +S9 standing for presence of metabolic activation, and –S9 standing for absence of metabolic activation

Method

Metabolic activation:
with and without
Metabolic activation system:
The test was performed in two experiments in the presence and absence of metabolic activation, with +S9 standing for presence of metabolic activation, and –S9 standing for absence of metabolic activation.
Test concentrations with justification for top dose:
Concentration 5000 μg/plate;
Concentration 2500 μg/plate;
Concentration 1250 μg/plate;
Concentration 625 μg/plate;
Concentration 313 μg/plate;
Concentration 156 μg/plate
Vehicle / solvent:
In a non-GLP pre-test, the solubility of the test item was tested in a concentration of 50 g/L in demineralized water, dimethyl sulfoxide (DMSO), ethanol and acetone.
The solid test item is sufficiently soluble in demin. water, only.
Based on the non-GLP pre-test, demin. water was chosen as vehicle, because the test item was sufficiently soluble, and this solvent does not have any effects on the viability of the bacteria or the number of spontaneous revertants in the tested concentrations.
Controls
Untreated negative controls:
not specified
Negative solvent / vehicle 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; 2-Amino-Anthracene
Remarks:
All mutagenic substances were stored as ready to use solution in the test facility in the deep freezer (-20 ± 5 °C). The respective positive control solution was thawed on the day of each experiment

Results and discussion

Test resultsopen allclose all
Key result
Species / strain:
S. typhimurium TA 97
Remarks:
test strains TA97a
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
True negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
True negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
True negative controls validity:
valid
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
True negative controls validity:
not examined
Positive controls validity:
valid
Key result
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
True negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
The test item Sodium phenylphosphinate showed no increase in the number of revertants in all bacteria strains in both experiments.
Nearly all negative and all strain-specific positive control values were within the laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly.

Applicant's summary and conclusion

Conclusions:
The test item Sodium phenylphosphinate showed no increase in the number of revertants in all bacteria strains in both experiments.
Nearly all negative and all strain-specific positive control values were within the laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly

Based on the results of this study it is concluded that Sodium phenylphosphinate is not mutagenic in the Salmonella typhimurium strains TA97a, TA98, TA100, TA102 and TA1535 in the absence and presence of metabolic activation under the experimental conditions in this study.
Executive summary:

Two valid experiments were performed.

The study procedures described in this report were based on the most recent OECD and EC guidelines.

The test item Sodium phenylphosphinate was tested in the Salmonella typhimurium reverse mutation assay with five strains of Salmonella typhimurium (TA97a, TA98, TA100, TA102 and TA1535).

The test was performed in two experiments in the presence and absence of metabolic activation, with +S9 standing for presence of metabolic activation, and –S9 standing for absence of metabolic activation.

Experiment 1:

In the first experiment, the test item (dissolved in demin. water) was tested up to concentra-tions of 5000 μg/plate in the absence and presence of S9-mix in the strains TA97a, TA98, TA100, TA102 and TA1535 using the plate incorporation method.

The test item showed no precipitates on the plates at any of the concentrations.

The bacterial background lawn was not reduced at any of the concentrations and no relevant decrease in the number of revertants was observed in all bacteria strains. The test item showed no signs of toxicity towards the bacteria strains in both the absence and presence of metabolic activation.

The results of this experiment showed that none of the tested concentrations showed a significant increase in the number of revertants in all tested strains, in the presence and the absence of metabolic activation.

Experiment 2:

Due to the first experiment, the test item was tested up to concentrations of 5000 μg/plate in the absence and presence of S9-mix in all bacteria strains using the pre-incubation method.

The test item showed no precipitates on the plates at any of the concentrations.

The bacterial background lawn was not reduced at any of the concentrations and no relevant decrease in the number of revertants was observed in all bacteria strains. The test item showed no signs of toxicity towards the bacteria strains in both the absence and presence of metabolic activation.

The results of this experiments showed that the test item caused no increase in the number of revertants in all bacteria strains compared to the solvent control, in both the absence and presence of metabolic activation. The test item did not induce a dose-related increase in thenumber of revertants colonies in all strains, in the presence and absence of metabolic acti-vation.

Based on the results of this study it is concluded that Sodium phenylphosphinate is not mutagenic in the Salmonella typhimurium strains TA97a, TA98, TA100, TA102 and TA1535 in the absence and presence of metabolic activation under the experimental conditions in this study.

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