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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:
2011
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study performed according to OECD test guideline No. 471 and in compliance with GLP without any deviation.
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report date:
2011

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)
Deviations:
no
Principles of method if other than guideline:
not applicable
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
4,4’-Bis[sec-alkyl(C10-C13)phenyl]iodonium tetrakis(pentafluorophenyl)borate
EC Number:
810-260-4
Cas Number:
1115251-57-4
IUPAC Name:
4,4’-Bis[sec-alkyl(C10-C13)phenyl]iodonium tetrakis(pentafluorophenyl)borate
Test material form:
other: Liquid (considered as solid due to its viscosity)
Details on test material:
- Name of test material (as cited in study report): PI 2080
- Physical state: Clear amber highly viscous liquid
- Analytical purity: >99%
- Lot/batch No.: 11GP0077
- Expiration date of the lot/batch: march 2012
- Storage condition of test material: at room temperature and protected form light

Method

Target gene:
Histidine gene of S. thyphimurium
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Details on mammalian cell type (if applicable):
not applicable
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
S9-mix from the livers of male Sprague-Dawley rats treated with Aroclor 1254
Test concentrations with justification for top dose:
Range-finding test and main experiments: 0.06, 0.19, 0.56, 1.67 and 5 mg/plate (all strains, with and without metabolic activation)
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: Ethanol 96º
- Justification for choice of solvent/vehicle: the solubility of the test item was evaluated in a standard solvent panel (milliQ water, ethanol 96%, DMSO
and corn oil). The test item was soluble in ethanol (96%) at a concentration of 50.0 mg/mL.
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Remarks:
See Table 7.6.1/1
Positive control substance:
4-nitroquinoline-N-oxide
9-aminoacridine
2-nitrofluorene
sodium azide
other: 2-aminoanthracene
Details on test system and experimental conditions:
METHOD OF APPLICATION: Experiment 1: in agar (plate incorporation), Experiment 2: preincubation + plate incorporation

DURATION
- Exposure duration: 48 hours at 37 °C

NUMBER OF REPLICATIONS: triplicates

DETERMINATION OF CYTOTOXICITY
- Method: growth assessment of the bacterial background lawn

OTHER: ACCEPTANCE CRITERIA: The reverse mutation assay was considered valid if the following criteria were met:
- The mean solvent control counts complied with historical data for each strain.
- The mean positive control counts complied with historical data for each strain.
Evaluation criteria:
The test item is considered as mutagenic if there is a concentration effect relationship and the revertant number is increased by 2 fold for TA98, TA100 and WP2(pKM101) and by 3 fold for TA1535 and TA1537, compared to vehicle control.
Statistics:
None

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity nor precipitates, but tested up to recommended limit concentrations
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: not applicable
- Effects of osmolality: not applicable
- Evaporation from medium: the test material is not classified as a VOC
- Water solubility: the test material was solubilised in ethanol to improve solubility
- Precipitation: none observed
- Other confounding effects: none

RANGE-FINDING/SCREENING STUDIES: performed in the S.typhimurium TA 100 strain by the direct incorporation procedure. A decrease in the number of revertant colonies >50% compared to solvent reference was observed. The lowest cytotoxic concentration was 5 mg/plate, used as the highest concentration in the test item formulation

COMPARISON WITH HISTORICAL CONTROL DATA: All tester strain cultures exhibit a characteristic number of spontaneous revertants per plate within the vehicle and positive controls ranges of the laboratory.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

None

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

PI 2080 is not mutagenic with and without metabolic activation in S. thyphimurium strains TA 98, TA 100, TA 1535 and TA 1537 and E. coli WP2 (pKM101).
Executive summary:

In a reverse gene mutation assay performed according to the OECD test guideline No. 471 and in compliance with GLP, S. typhimurium strains TA 98, TA 100, TA 102 and TA 1535 and E. coli WP2(pKM101) were exposed to PI 2080 diluted in ethanol both in the presence and absence of metabolic activation system (10% liver S9 in standard co-factors) using the plate incorporation method. In a preliminary toxicity assay, citotoxicity was assessed between 0.06 and 5 mg/plate on TA100. The lowest cytotoxic concentration was 5 mg/plate, used as the highest concentration in the test item formulation for the two main experiments. In the second experiment, preincubation was added to the experimental procedure.

The vehicle (ethanol) control plates gave counts of revertant colonies within the normal range. All of the positive control chemicals used in the test induced marked increases in the frequency of revertant colonies, both with or without metabolic activation.

No significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, at any dose level either with or without metabolic activation.

 

In these experimental conditions, PI 2080 was not mutagenic with and without metabolic activation in S. thyphimurium strains TA 98, TA 100, TA 1535 and TA 1537 and E. coli WP2(pKM101).

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