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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1984-02-12 to 1984-02-25
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
No analytical provided on test substance, an E. coli strain was not included in study, and negative result was not confirmed in a repeat assay and no justification for not repeating assay was provided. However the study was GLP-compliant, positive and vehicle control were included and the study was performed in the presence and absence of metabolic activation.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1984
Report date:
1984

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
No analytical provided on test substance, an E. coli strain was not included in study, and negative result was not confirmed in a repeat assay and no justification for not repeating assay was provided.
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Test material form:
liquid
Specific details on test material used for the study:
- Name of test material (as cited in study report): 5601-22-20, Order #J-203
- Analytical purity: purity was the responsibility of the sponsor
- Physical state: yellow liquid
- Storage condition of test material: the test substance was stored at room temperature in a clear glass bottle

Method

Target gene:
histidine locus
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA98, TA100, TA1535, TA1537 and TA1538
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
Aroclor 1254 induced rat liver S9
Test concentrations with justification for top dose:
100, 333, 1000, 3333 and 10,000 ug/plate
Vehicle / solvent:
- Vehicle(s)/solvent(s) used: deionized water
- Justification for choice of solvent/vehicle: test substance was determined to be soluble in water
Controlsopen allclose all
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
deionized water
True negative controls:
no
Positive controls:
yes
Positive control substance:
sodium azide
Remarks:
without metabolic activation Migrated to IUCLID6: used for TA1535 and TA100 at 10 ug/plate
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
deionized water
True negative controls:
no
Positive controls:
yes
Positive control substance:
9-aminoacridine
Remarks:
without metabolic activation Migrated to IUCLID6: used for TA1537 at 150 ug/plate
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
deionized water
True negative controls:
no
Positive controls:
yes
Positive control substance:
2-nitrofluorene
Remarks:
without metabolic activation Migrated to IUCLID6: used for TA1538 and TA98 at 5 ug/plate
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
Remarks:
deionized water
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene used for all strains at 5 ug/plate
Remarks:
with metabolic activation
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48-72 hours
- Selection time (if incubation with a selection agent): 48-72 hours (simultaneous with exposure)

SELECTION AGENT (mutation assays): histidine

NUMBER OF REPLICATIONS: 3 (test substance), 2 (positive and vehicle control)

DETERMINATION OF CYTOTOXICITY
- Method: reduction in bacterial background lawn


Evaluation criteria:
A positive result was defined as a reproducible, dose-related increase in the number of histidine-independent colonies. This dose-response relationship occasionally necessitates slight modifications of the original doses in a repeat assay. If the solvent control was within one standard deviation of the historical mean for control values and the test substance produced the highest increase equal to or greater than three times the solvent control value, the test substance was considered positive. A negative result was defined as the absence of a reproducible increase in the number of histidine-independent colonies.
Statistics:
No data

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium, other: TA98, TA100, TA1535, TA1537 and TA1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not specified
Remarks:
but no toxicity was observed up to 10000 ug/plate in the range-finding assay.
Vehicle controls validity:
valid
Untreated negative controls validity:
not applicable
Positive controls validity:
valid
Additional information on results:
RANGE-FINDING/SCREENING STUDIES:
A preliminary toxicity assay was performed with TA1538 and TA100 in the presence and absence of metabolic activation. Tester strains were treated with the test substance at dose levels of 100-10,000 µg/plate for 48 hours using the plate incorporation assay. Following exposure, background lawn and spontaneous revertants were observed and scored as normal growth, inhibited growth or no growth. Inhibition was scored by the presence of pindot colonies and the absence of a confluent lawn of bacteria. No toxicity was observed up to 10000 ug/plate in the presence or absence of metabolic activation.

COMPARISON WITH HISTORICAL CONTROL DATA:
All solvent and positive control values were within the acceptable limits of mean historical data.

Any other information on results incl. tables

all strains/cell types tested

Applicant's summary and conclusion

Conclusions:
The test substance was evaluated for induction of mutagenicity in the Ames Salmonella/Microsome Plate test in the presence and absence of metabolic activation using S. typhimurium tester strains TA98, TA100, TA1535, TA1537 and TA1538. The test substance failed to induce reverse mutations in any of the tester strains both in the presence and absence of metabolic activation up to concentration levels of 10,000 ug/plate.