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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:
1992-04-10 to 1992-07-10
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study is performed according to Guideline 471, under GLP and is well reported.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report date:
1992

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

Constituent 1
Chemical structure
Reference substance name:
Pentafluoroiodoethane
EC Number:
206-566-7
EC Name:
Pentafluoroiodoethane
Cas Number:
354-64-3
Molecular formula:
C2F5I
IUPAC Name:
pentafluoroiodoethane
Details on test material:
- Name of test material (as cited in study report): Pentafluorethyljodid
- Molecular formula (if other than submission substance): C2 F5 J
- Physical state: colourless gas
- Analytical purity: about 97 -98 %
- Impurities (identity and concentrations): Tetrafluorethylene; about 1.19 % to 1.6 %
- Purity test date: 1992-04-07
- Lot/batch No.: 4847 (1286524)
- Expiration date of the lot/batch: August 1993
- Radiochemical purity (if radiolabelling):
- Storage condition of test material: dark at room temperature

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
S. typhimurium TA 1538
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced liver S9 homogenate mixture
Test concentrations with justification for top dose:
0.8 vol. %/plate to 20.1 vol. %/Plate proved to be not toxic to the bacteraial strains.
For mutagenicity testing 18.1 vol %/plate was chosen as the highest dose in the first main experiment.
Vehicle / solvent:
air
Controlsopen allclose all
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
without S9 mix

Migrated to IUCLID6: TA 100, TA 1535
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
without S9 mix

Migrated to IUCLID6: TA 1537
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
without S9 mix

Migrated to IUCLID6: TA 98, TA 1538
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: 2-Aminoanthracene for all 5 tester strains
Remarks:
with S9 mix
Details on test system and experimental conditions:
Preliminary experiment was performed in all tester strains using three plates per dose. In combination with the main experiment, toxicity testing was performed as follows:
the same doses of the test compound as in the main experiment were tested with 0.1 mL of 10-6 dilution of the overnight culture of TA 100 and plate with histidine and biotin rich agar (3 plates per dose). The solvent control is compared with the number of colonies per plate in presence of the test compound. Results are given as a ration of these values (= surviving fraction).
For the mutagenicity testing the prepared liquid top agar is poured into a petridish with minimal agar. In this way pretreated plates are arranged by doses and placed open in an exsictor which is connected to a gas sampler. The exsicator is inflated with gas-air mixture by an air calibrated rotameter for approx. 10 minutes. The inflated gas-samplers are sent to the laboratory to analyze the exact concentration of gas (in the gas-air mixture). After incubation for 48 hours at approx. 37°C in the dark colonies (his+ revertants) are counted. Four independent experiments were performed.
Evaluation criteria:
The article is classified mutagenic if either of the following conditions under a) and b) is achieved:
a) a test article produces at least a 2-fold increase in the mean number of revertants per plate of at least one of the tester strains over the mean number of revertants per plate of the appropriate vehicle control at complete bacterial background lawn.
b) a test acticle induces a dose-related increase in the mean number of revertants per plate of at least one of the tester strains over the mean number of revertants per plate of the appropriate vehicle control in at least two to three concentrations of the test article at complete bacterial background lawn.
The test results must be reproducble.

Results and discussion

Test resultsopen allclose all
Species / strain:
S. typhimurium TA 1537
Metabolic activation:
with and without
Genotoxicity:
positive
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1535
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 100
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Based on the results of this Ames test it can be stated that the test substance is mutagenic with and without metabolic activation.
Executive summary:

The test compound was tested for mutagenicity with the tester strains S. typhimurium TA 1535, TA 1537, TA 1538, TA 98 and TA 100.

The mutagenicity studies were coducted with and without S9 mix derived from Aroclor induced rat liver homogenate. A dose range of 5 or 6 different doses from 0.8 vol. %/plate to 38.6 vol. %/plate was used.

The test substance proved to be not toxic to the bacterial strains. 38.6 vol. %/plate was tested as top dose level for mutagenicity study.

In the absence of the metabolic activation system, the test compond gave a dose dependent increase in the number of revertant colonies with the bacterial strain TA 1537. In the presence of metabolic activation, treatment of cells with the test compound results in relevant increases in the number of revertant colonies with the Salmonella strain TA 1537.

Based on the results of this test it can be stated that the test substance is mutagenic with and without metabolic activation.