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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study was conducted by a GLP accredited laboratory using OECD Testing Guideline 471.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report date:
2012

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Reference substance name:
1H-Imidazolium, 3-ethyl-1-methyl-, C9-14-branched alkylbenzensulfonates
IUPAC Name:
1H-Imidazolium, 3-ethyl-1-methyl-, C9-14-branched alkylbenzensulfonates
Constituent 2
Reference substance name:
EMI-DBS
IUPAC Name:
EMI-DBS
Constituent 3
Reference substance name:
1065642-34-3
Cas Number:
1065642-34-3
IUPAC Name:
1065642-34-3
Test material form:
semi-solid (amorphous): gel
Remarks:
migrated information: paste
Details on test material:
Product name: EMI-DBS
Appearance: Yellow paste
Condition of storage: Normal temperature

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9 mix
Test concentrations with justification for top dose:
Based on the results of preliminary range-finding test, the main test was performed on 5 dose levels with and without metabolic activation, as follows:

In the absence of S9 mix: TA100, TA1537 = 0, 156, 313, 625, 1250 and 2500 µg/plate and TA98, TA1535, WP2uvrA = 0, 313, 625, 1250, 2500, 5000 µg/plate
In the presence of S9 mix: All strains = 0, 313, 625, 1250, 2500, 5000 µg/plate
Vehicle / solvent:
Dimethyl sulfoxide (DMSO)
Controls
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
9-aminoacridine
sodium azide
other: 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide (AF-2); 2-aminoanthracene
Remarks:
The control substances were recommended by the relevant OECD and NIER test guidelines
Details on test system and experimental conditions:
Supplier of bacterial strains: Molecular Technology Inc.
Storage method: Kept in freezer
Storage temperature: -80°C (deep freezer DF9007)
Composition: Bacterial strain = 0.8 ml, DMSO = 0.07 ml

Pre-cultivation conditions
Nutrient broth: Name - No. 2, Manufacturer - Oxoid, Lot No. - 588285
Cultivation time: 10 hours (stop incubation in the early stationary phase)
Shaking incubator: Model - SHKE-5000-1CE, Manufacturer - Barnstead International USA
Incubation method: Shaking type - rotation (RPM: 180/min), Rotation diameter - 2.54 cm
Culture vessel: Type - Erlenmeyer flask, Capacity - 50 ml
Volume of culture medium: 15 ml
Volume of inoculum: 30 µl

Medium: Top Agarr; Minimum glucose agar plate; Vogel-Bonner medium E(10x)
Evaluation criteria:
The result was judged as "positive" if there was a concentration-related increase over the range tested and/or a reproducible increase at one or more concentrations in the number of revertant colonies per plate in at least one strain with or without metabolic activation system.
Statistics:
The statistical method for analysis of the results was not applied in this study.

Results and discussion

Test results
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
no cytotoxicity
Vehicle controls validity:
not specified
Untreated negative controls validity:
valid
Positive controls validity:
not specified
Additional information on results:
Regardless of the metabolic activation system, the number of revertant colony did not show an increase compared with the number of revertant colony of the negative control group.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Cytotoxicity was observed in 2500 µg/plate dose levels (TA100, TA1537 strains) and in the 5000 µg/plate dose levels (TA98, TA1535 strains) in the absence of metabolic activation system. In the presence of metabolic activation system, cytotoxicity was observed in the 5000 µg/plate dose levels (TA98, TA100 and TA1537 strains). When compared to the negative control, significant increases in the number of revertant colonies were not observed in the 5 strains regardless metabolic activation system.

The sterility of the solvent and the S9 mix were certified by the sterility test. It was counted that the number of revertant colonies of positive control groups and negative control groups were within or close to the range of the historical data. Therefore this test was performed properly.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

The EMI-DBS was found to not induce reverse mutation under the conditions of the study.
Executive summary:

The genetic toxicity in vitro of the test substance was determined in accordance with the OECD Guideline for Testing of Chemicals 471. The mutagenic potential of EMI-DBS in bacteria was evaluated using the bacterial reverse mutation study. The study was performed using the preincubation method using four histidine-requiring strains of Salmonella typhimurium TA98, TA100, TA1535 and TA1537, and one tryptophan-requiring strain of Escherichia coli WP2uvrA in the presence and absence of metabolic activation. Based on the results of preliminary range-finding test, the main test was performed at the following 5 dose levels:

- in the absence of metabolic activation system (S9 mix (-)): TA100, TA1537 = 0, 156, 313, 625, 1250, 2500 µg/plae and TA98, TA1535, WP2uvrA = 0, 313, 625, 1250, 2500, 5000 µg/plate

- in the presence of metabolic activation (S9 mix (+)): 0, 313, 625, 1250, 2500, 5000 µg/plate.

There was no increase in the number of revertant colonies seen in TA98, TA100, TA1535, TA1537 and WP2uvrA strains when compared with the negative control groups in the presence and absence of metabolic activation system. Based on these findings, it has been concluded that EMI-DBS does not induce reverse mutation in the bacterial strains investigated in this study.

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