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Toxicological information

Genetic toxicity: in vitro

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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:
from 15th March 1982 to 1st September 1982
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study report which was conducted following the procedure of Ames test fulfill the basic scientific principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1982
Report Date:
1982

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
not specified
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
CAS No. 79-38-9
Storage conditions: room temperature
CMA sample: 8185-35

Method

Target gene:
Salmonella typhimurium histidine (his) reversion system.
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
S9(from the livers of Sprague-Dawley adult male rates induced by Aroclor 1254)
Test concentrations with justification for top dose:
Test article: 12.5, 15, 25, 30 and 50%
S9 levels: 0, 5, 12.5mg/plate(0, 20, 50µl s9 fraciton)
Vehicle / solvent:
none
Controlsopen allclose all
Untreated negative controls:
yes
Remarks:
the test without the test item was the negative control
Negative solvent / vehicle controls:
no
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
1.0 µg/plate, TA100, TA-1535

Migrated to IUCLID6: used for the test without the metabolic activation
Untreated negative controls:
yes
Remarks:
the test without the test item was the negative control
Negative solvent / vehicle controls:
no
True negative controls:
no
Positive controls:
yes
Remarks:
used for the test without the metabolic activation
Positive control substance:
2-nitrofluorene
Remarks:
1.0 µg/plate, TA98
Untreated negative controls:
yes
Remarks:
the test without the test item was the negative control
Negative solvent / vehicle controls:
no
True negative controls:
no
Positive controls:
yes
Remarks:
used for the test without the metabolic activation
Positive control substance:
9-aminoacridine
Remarks:
50 µg/plate, TA1537
Untreated negative controls:
yes
Remarks:
the test without the test item was the negative control
Negative solvent / vehicle controls:
no
True negative controls:
no
Positive controls:
yes
Positive control substance:
benzo(a)pyrene
Remarks:
2.5 µg/plate, TA100, TA98, TA1537

Migrated to IUCLID6: used for the test with the metabolic activation
Untreated negative controls:
yes
Remarks:
the test without the test item was the negative control
Negative solvent / vehicle controls:
no
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-anthramine
Remarks:
2.5 µg/plate, TA1535
Details on test system and experimental conditions:
METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 24h
- Exposure duration: Incubated at 37°C for 24-48 hours


NUMBER OF REPLICATIONS: triplicates

The reaction mixtures for the assays were prepared in 13 x 100 mm tube by mixing together the following :
1. 0.05 - 0.2 ml bacterial suspension.
2. 0.5 ml S9 mix, in test with metabolica activation.
3. 0.5 ml phosphate buffer pH 7.4 in test without metabolic activation
3. 2.0 ml molten agar supplemented with 0.5 mM histidine-biotin solution
4. the test item as gas is mixed with an appropriate amount of air to achieve the desidered concentration ( that is 50% test gas concentration is achieved by mixing air at 2 liters/minute with the gas at 2 liters/minute)

Aliquots of each mixture were poured onto agar plates. The mixture is allowed to flow through the chamber until the theoretical tgg time period is achieved.

The prepared plates were incubated at 37°C for 48 h at which time the revertant colonies were counted.
Evaluation criteria:
The number of revertants, colony-producing bacteria is counted after a forty-eight days to seventy-two hours growth period. A dose related increase in revertants over spontaneous background is considered a positive test result.
Statistics:
no data. Only the arithmetic mean for the number of mutants per plate is reported, see data attched to the field "attached background material".

Results and discussion

Test results
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:
cytotoxicity
Remarks:
at a dose/plate of the test item of 50% with strains TA100 and TA 1535
Vehicle controls validity:
not specified
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Due to a slight elevation of the number of revertants obtained with strains TA-100 and TA-1535 a t 25% gas in air mixture, this test will be repeated using all four tester strains a t levels of 15%, 25% and 30% CTFE.
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

The results of the Ames mutagenicity test on chlorotrifluoroethylene (CTFE) showed that the test item not induce a mutagenic response in salmonella typhimurium strains TA100, TA98, TA1537, TA1535 in the presence or absence of rat liver activating enzymes.
Executive summary:

Four mutant strains of Salmonella typhimurium(TA-100, TA-98, TA-1537 and TA-1535) were used in this assay.The strains were treated with the test substance with and without the activation enzyme. Appropriate concentrations of the gas at room temperature at levels of 12.5, 15, 25, 30 and 50% for approximately 24 hours were introduced. The test compound did not induce a mutagenic response in Salmonella typhimurium strains TA-100, TA-98, TA-1537 and TA-1535in the presence or absence o f rat liver activating enzymes.However, a toxic effect was observed at the 50% dose level with the strains TA-100 and TA-1535.

Since no E.coli and S.typhimurium T102 strains were used, no detection of AT base pair at the primary reversion site was possible.