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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:
March 31, 1995 - April, 13, 1995
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report date:
1995

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Version / remarks:
(1983)
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: European Economic Community (EEC), Directive 92/69/EEC. Annex V of the EEC Directive 67/548/EEC, Part B: Methods for the Determination of Toxicity; B.14: "Other Effects-Mutagenicity: Salmonella typhimurium Reverse Mutation Assay". (1992)
Deviations:
no
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
422-150-1
EC Name:
-
Molecular formula:
Hill formula: Mg4.3 Al2(OH)12.6 (CO3)0-0.75 (ClO4)0.5-2.0 . (0-5)H2O CAS formula: Mg4.3 Al2(OH)12.6 (CO3)0-0.75 (ClO4)0.5-2.0 . (0-5)H2O
IUPAC Name:
Aluminium-magnesium-carbonate-hydroxide-perchlorate-hydrate
Test material form:
solid: particulate/powder
Details on test material:
- Appearance: white powder
- Storage condition of test material: at room temperature in the dark

Method

Target gene:
- S. typhimurium: Histidine gene
Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Metabolic activation:
with and without
Metabolic activation system:
Rat liver S9-mix induced by Aroclor 1254 (500 mg/kg bw).
Test concentrations with justification for top dose:
Experiment 1
Preliminary test (without and with S9) TA100: 3, 10, 33, 100, 333, 1000, 3330 and 5000 µg/plate
Main study: TA1535, TA1537 and TA98:
Without and with S9-mix: 100, 333, 1000, 3330 and 5000 µg/plate
Experiment 2: All 4 strains
Without and with S9-mix: 100, 333, 1000, 3330 and 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Test compound was suspended or dissolved in DMSO and DMSO has been accepted and approved by authorities and international guidelines.
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
Positive controls:
yes
Positive control substance:
methylmethanesulfonate
Remarks:
without S9 Migrated to IUCLID6: 650 µg/plate in DMSO for TA100
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
Positive controls:
yes
Positive control substance:
other: daunomycine 4 µg/plate in saline for TA98
Remarks:
without S9
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
Positive controls:
yes
Positive control substance:
other: 9-aminoacridine 60 µg/plate in saline for TA1537
Remarks:
without S9
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
Positive controls:
yes
Positive control substance:
other: sodium azide 1 µg/plate in saline for TA1535
Remarks:
without S9
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
DMSO
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene 5 µg/plate in DMSO for TA1535 and TA1537, and 0.5 µg/plate in DMSO for TA98 and TA100.
Remarks:
with S9
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hour

NUMBER OF REPLICATIONS:
- Doses of the test substance were tested in triplicate in each strain. Two independent experiments were conducted.

NUMBER OF CELLS EVALUATED: 10E8 per plate

DETERMINATION OF CYTOTOXICITY
- Method: The reduction of the bacterial background lawn, the increase in the size of the microcolonies and the reduction of the revertant colonies.

OTHER EXAMINATIONS:
- The presence of precipitation of the test compound on the plates was determined.
Evaluation criteria:
A test substance is considered negative (not mutagenic) in the test if:
a) The total number of revertants in any tester strain at any concentration is not greater than two (2) times the concurrent control, with or without metabolic activation.
b) The negative response should be reproducible in at least one independently repeated experiment.

A test substance is considered positive if:
a) It induces at least a two-fold, dose related increase in the number of revertants with respect to the number induced by the solvent control in any of the tester strains, either with or without metabolic activation. However, any mean plate count of less than 20 is considered to be not significant. If in the first test the test substance showed only a positive response at one or two concentrations, the assay was repeated with doses just below and exceeding those showing positive effects in the first test.
b) The positive response should be reproducible in at least one independently repeated experiment.

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:
In both experiments a clear decrease in the number of revertants in strains TA100 and TA1537 in the absence of S9-mix was observed.
Vehicle controls validity:
valid
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Precipitation was observed in the top agar at dose levels of 1000 µg/plate and upwards but precipitation was not observed at the end of the incubation period.

RANGE-FINDING/SCREENING STUDIES:
- No reduction of the bacterial background lawn was observed. A dose-related decrease was observed in the number of revertants.

COMPARISON WITH HISTORICAL CONTROL DATA:
- The negative and strain-specific positive control values were within our laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
The bacterial background lawn was not reduced at all concentrations tested. In both experiments a clear decrease in the number of revertants in strains TA100 and TA1537 in the absence of S9-mix was observed.

Applicant's summary and conclusion

Conclusions:
Alcamizer 5 is not mutagenic in the Salmonella typhimurium reverse mutation assay, performed according to OECD 471 guideline and GLP principles with or without metabolic activation.
Executive summary:

The genetic toxicity of Alcamizer 5 was assessed using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains, in accordance with OECD 471 guideline and GLP principles. No precipitation was observed at the end of the incubation period. The bacterial background lawn was not reduced at all concentrations tested. In both experiments a clear decrease in the number of revertants in strains TA100 and TA1537 in the absence of S9-mix was observed. All bacterial strains showed negative responses up to 5000 µg/plate, i.e. no biologically significant dose-related increase in the number of revertants with or without metabolic activation was seen in two independently repeated experiments. The negative and strain-specific positive control values were within the laboratory historical control data ranges indicating that the test conditions were adequate and that the metabolic activation system functioned properly. Based on the results of this study it is concluded that Alcamizer 5 is not mutagenic in the Salmonella typhimurium reverse mutation assay with or without metabolic activation.

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