Registration Dossier

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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: conducted to OECD/EC guidelines with GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes (incl. certificate)
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Trisodium [carboxy(oxido)methyl]phosphonate
- Substance type: Powder
- Physical state: Solid
- Lot/batch No.: LIC 613/04
- Storage condition of test material: Room temperature in the dark

Method

Species / strainopen allclose all
Species / strain / cell type:
E. coli WP2 uvr A
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
S9 from livers of Sprague-Dawley rats
Test concentrations with justification for top dose:
50, 150, 500, 1500, 5000 micrograms/plate. (In the second repeat experiment, the doses used were the same except for the WP2uvrA- strain which was allocated an amended dose range of 150, 500, 1500, 3000 and 5000 micrograms/plate. The 3000 microgram/plate was introduced to confirm a better dose-response relationship and reproducibility as there were small increases in revertant colony frequency seen in experiment 1).
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: Trisodium [carboxy(oxido)methyl]phosphonate was fully soluble in sterile distilled water at 50 mg/mL in solubility checks performed in house. Sterile distilled water was therefore selected as the vehicle.
Controlsopen allclose all
Untreated negative controls:
yes
Remarks:
spontaneous mutation
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
N-ethyl-N-nitro-N-nitrosoguanidine
Positive controls:
yes
Positive control substance:
9-aminoacridine
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
Positive controls:
yes
Positive control substance:
other: 2-Aminoanthracene
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 3 replicates/dose/strain
Evaluation criteria:
There are several criteria for determining a positive result, such as dose-related increase in revertant frequency over the dose range tested and/or a reproducible increase at one or more concentrations in at least one bacterial strain with or without metabolic activation.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
In the first experiment, there was a small statistically significant increase in revertant colony frequency seen in the WP2uvr2- strain, without S9, at 5000 micrograms/plate. This response was not considered to be toxicologically significant as it was non-reproducible.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Trisodium [carboxy(oxido)methyl]phosphonate is considered to be non-mutagenic.
Executive summary:

In a reverse gene mutation assay in bacteria, strains TA 1535, TA 1537, TA 98 and TA 100 of S. typhimurium and E. coli WP2 uvr A  were exposed to Trisodium [carboxy(oxido)methyl]phosphonate at concentrations of 50, 150, 500, 1500, 5000 micrograms/plate in the presence and absence of mammalian metabolic activation. (In the second repeat experiment, the doses used were the same except for the WP2uvrA- strain which was allocated an amended dose range of 150, 500, 1500, 3000 and 5000 micrograms/plate).

 

The positive controls induced the appropriate responses in the corresponding strains.  

This study satisfies the requirement for Test Guideline OECD 471 for in vitro mutagenicity (bacterial reverse gene mutation) data.