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:
other information
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study in accordance to OECD GL

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
1,1,1,3,3-pentachlorobutane
EC Number:
244-691-9
Cas Number:
21981-33-9
Molecular formula:
C4H5Cl5
IUPAC Name:
1,1,1,3,3-pentachlorobutane
Details on test material:
- Name of test material (as cited in study report): 1,1,1,3,3-pentachlorobutane
- Molecular formula (if other than submission substance): same as submission substance
- Molecular weight (if other than submission substance): same as submission substance
- Smiles notation (if other than submission substance): same as submission substance
- Structural formula attached as image file (if other than submission substance): see Fig.
- Substance type: organic
- Physical state: liquid
- Analytical purity: 90%
- Impurities (identity and concentrations):
- Purity test date: 09/09/99
- Lot/batch No.: 99350L08
- Expiration date of the lot/batch: 13/09/2000
- Stability under test conditions: stable
- Storage condition of test material: at room temeprature in the dark

Method

Species / strainopen allclose all
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Species / strain / cell type:
E. coli WP2 uvr A
Metabolic activation:
with and without
Metabolic activation system:
S9-mix
Test concentrations with justification for top dose:
Preliminary test (TA100 and WP2uvrA, +/- S9-mix): 3, 10, 33, 100, 333, 1000, 3330, 5000 ug/plate
Main test
see table 1
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
Controls
Negative solvent / vehicle controls:
yes
Positive controls:
yes
Positive control substance:
other: -S9-mix: Sodium azide (TA1535), 9-aminoacridine (TA1537), methylmethane sulfonate (TA100), Daunomycine (TA98), 4-nitroquinolone (WP2uvrA)/ +S9-mix: 2-aminoanthracene (all strains)
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period:
- Exposure duration: 48 h
-
DETERMINATION OF CYTOTOXICITY
- Method: reduction of the bacterial background lawn, redction of revertant colonies
Evaluation criteria:
number of revertant colonies induced by the substance is 2 times greater than the revertants induced by the negative control in any of the tetsted strains, either with or without metabolic activation. The positive response has to be reproducible in at least 1 independent experiment.

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:
cytotoxicity
Remarks:
Genreally observed at > 333 ug/plate and >1000 ug/plate in all the S. tiphymurium strains with and without metabolic activation, respectively.
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
without
Genotoxicity:
positive
Remarks:
Positive results observed in the preliminary test and in the main test (experiment 2). Negative responses observed in experiments 3 and 4.
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
Only minimal toxicity observed at > 1000 ug/plate
Vehicle controls validity:
valid
Positive controls validity:
valid
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
Only minimal toxicity observed at 5000 ug/plate.
Vehicle controls validity:
valid
Positive controls validity:
valid
Additional information on results:
Positive results were observed for WP2uvrA in the absence of S9-mix in the preliminary test and in the main test (experiment 2). The experiment was repeated by preventing the test substance evaporation (experiments 3 and 4). Negative results were observed in the repeated experiments

TEST-SPECIFIC CONFOUNDING FACTORS
- Evaporation from medium: In experiments 3 and 4 the plates were sealedwith parafilm to avoid possible evaporation of the test substance
- Precipitation: precipitation of the test substance was observed at the start of the incubation. At the end of the incubation no precipitation was visible anymore.

COMPARISON WITH HISTORICAL CONTROL DATA:
The positive results observed for WP2uvrA in the preliminary test (up to 3.5 fold the number of revertant colonies observed in comparison to vehicle controls) was within the historical control data and was related to a low vehicle control data (average of 6 revertant colonies vs the historical control mean value of 12). In experiment 4 an increase up to 2 fold in the number of revertant colonies was observed for 1,1,1,3,3,-pentafluorobutane in comparison to vehicle control. Also in this case the increase was within the mean historical control value.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Overall the substance was judged as not mutagenic in all the tested strains both in the presence and in the absence of metabolic activation.