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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:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP-Guideline study (OECD). Due to structural similarities of the registered substance trans-ß-ionone (CAS 79-77-6) and the used test substance (mixture of α- and β-isomers, CAS 8013-90-9) the data could be taken into account for assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1980
Report Date:
2004

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes
Remarks:
RCC-CCR
Type of assay:
bacterial reverse mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): Ionantheme 100%
- Physical state: colourless to pale yellow liquid
- Analytical purity: 85.1% (sum of 2 isomers)
- Batch No.: 9000533813
- Expiration date: April 14, 2004
- Storage condition of test material: room temperature

Method

Target gene:
histidin operon
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 102
Metabolic activation:
with and without
Metabolic activation system:
phenobarbital/beta-naphthoflavone induced rat liver microsomal activation (S9)
Test concentrations with justification for top dose:
10, 33, 100, 333, 1000, 2500 and 5000 µg/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: ethanol (purity > 99%, MERCK, D-64293 Darmstadt)
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: sodium azide (TA 1535, TA 100), 4-nitro-o-phenylene-diamine (TA 1537, TA 98), methyl methane sulfonate (TA 102), 2-aminoanthracene (TA 1535, TA 537, TA 98, TA 100, TA 102)
Remarks:
without metabolic activation
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene
Remarks:
with metabolic activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation) (experiment I)
DURATION
- Exposure duration: at least 48 h, 37°C

METHOD OF APPLICATION: preincubation (experiment II)
DURATION
- Preincubation period: 60 min, 37 °C
- Exposure duration: at least 48 h, 37°C

NUMBER OF REPLICATIONS: 3

OTHER
- The colonies were counted using the AUTOCOUNT
- The plates showing impaired background growth were evaluated manually

Evaluation criteria:
- Test material is considered as a mutagen if a biologically relevant increase in the number of revertants exceeding the threshold of twice (strains TA98, TA100 and TA102) or three times (strains TA1535 and TA1537) the colony count of the corresponding solvent control is observed.
- A dose dependent increase is considered biologically relevant if the threshold is exceeded at more than one concentration.
- An increase exceeding the threshold at any one concentration is judged as biologically relevant if reproduced in an independent second experiment.
- A dose dependent increase in the number of revertant colonies below the threshold is regarded as an indication of a mutagenic potential if reproduced in an independent second experiment.
- However, whenever the colony counts remain within the historical range of negative and solvent controls such an increase is not considered biologically relevant

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:
datails see "Any other information on results incl. tables"
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Species / strain:
S. typhimurium TA 102
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
datails see "Any other information on results incl. tables"
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
ADDITIONAL INFORMATION ON CYTOTOXICITY:
- Reduced background growth was observed in all strains with and without metabolic activation.
- Toxic effects, evident as a reduction in the number of revertants, were observed in all strains with and without metabolic activation.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

- Toxic effects, evident as a reduction in the number of revertants, were observed in strain TA 102 with and without metabolic activation at 5000 µg/plate and in strains TA 1537 (100 – 5000 µg/plate) and TA 100 at 1000 µg/plate with metabolic activation in experiment I. In experiment II, toxic effects were observed with and without metabolic activation in all strains used.

- No substantial increase in revertant colony numbers of any of the five tester strains at any concentration level in the presence or absence of metabolic activation.

- The positive controls showed a distinct increase of induced revertant colonies as expected

Applicant's summary and conclusion