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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:
01/2009-04/2009
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP-study according to OECD guideline 471

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Test Article I.D.: Dowanol™ TPnB-H Glycol Ether
Chemical Name: Reaction mass of α-butyl-ω-hydroxy-poly(oxy(methyl-1,2-ethanediyl)) (polypropylene glycol monobutyl ether and 3,6,9,12-Tetraoxahexadecan-1-ol, tetramethyl- (Tetrapropylene glycol monobutyl ether)
Test Article Lot No.: WK191920K1
Test Article CAS Nos.: Polypropylene glycol monobutyl ether: 9003-13-8 & Tetrapropylene glycol n-butyl ether: 107849-33-2
Test Article Purity: 100% Dowanol™ TPnB-H Glycol Ether
Test Article Description: brown to coffee color liquid
Storage Conditions: room temperature in the dark without desiccant

Method

Target gene:
Selected histidine loci of several strains of Salmonella typhimurium and the tryptophane locus of Escherichia coli strain WP2 uvrA.
Species / strainopen allclose all
Species / strain:
S. typhimurium TA 1535, TA 1537, TA 98 and TA 100
Details on mammalian cell lines (if applicable):
not applicable
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-induced rat liver S9
Species / strain:
E. coli WP2 uvr A
Details on mammalian cell lines (if applicable):
not applicable
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-induced rat liver S9
Test concentrations with justification for top dose:
initial toxicity mutation assay: 1.5, 5.0, 15, 50, 150, 500, 1500 and 5000 μg per plate
confirmatory mutation assay: 15, 50, 150, 500, 1500 and 5000 μg per plate
Vehicle:
Dimethyl sulfoxide (DMSO)
Controls
Negative controls:
yes
Solvent controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
other: 2-aminoanthracene; 2-nitrofluorene;sodium azide; 9-aminoacridine; methyl methanesulfonate
Details on test system and conditions:
METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min
- Exposure duration: 56 +/- 6 hours
- Expression time (cells in growth medium): 56 hours
- Selection time (if incubation with a selection agent): 56 hours

SELECTION AGENT (mutation assays): histidine (S.typhimurium strains); tryptophane (E.coli)

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
- Method: The condition of the bacterial background lawn was evaluated for evidence of test article toxicity by using a dissecting microscope.
Evaluation criteria:
For the test article to be evaluated positive, it must cause a reproducible, concentration-related increase in the mean revertants per plate of at least one tester strain over a minimum of two increasing concentrations of test article. Data sets for tester strains TA98, TA1535, TA1537 and WP2 uvrA were judged positive if the increase in mean revertants at the peak of the response was equal to or greater than 3.0-times the mean vehicle control value. Data sets for tester strains TA100 were judged positive if the increase in mean revertants at the peak of the response was equal to or greater than 2.0-times the mean vehicle control value.
Statistics:
not available

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:
yes
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.
Species / strain:
E. coli WP2 uvr A
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity:
yes
Vehicle controls valid:
yes
Negative controls valid:
yes
Positive controls valid:
yes
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

TPnB-highers did not induce gene mutations in bacteria with and without metabolic activation under the conditions of this study.
Executive summary:

The test article, Dowanol™ TPnB-H Glycol Ether, was tested in the Bacterial Reverse Mutation Assay using Salmonella typhimurium tester strains TA98, TA100, TA1535 and TA1537 and Escherichia coli tester strain WP2 uvrA in the presence or absence of Aroclor-induced rat liver S9. The assay was performed in two phases using the preincubation method. The first phase, the initial toxicity-mutation assay, was used to establish the dose-range for the confirmatory mutagenicity assay and to provide a preliminary mutagenicity evaluation. The second phase, the confirmatory mutagenicity assay, was used to evaluate and confirm the mutagenic potential of the test article. Dimethyl sulfoxide (DMSO) was selected as the solvent of choice based on the solubility of the test article and compatibility with the target cells. The test article formed a soluble and clear solution in DMSO at approximately 500 mg/mL, the maximum concentration tested. In the initial toxicity-mutation assay, the maximum concentration tested was 5000 μg per plate, which is the maximum concentration required by test guidelines. This concentration was achieved using a concentration of 100 mg/mL and a 50 μL plating aliquot. The concentrations tested were 1.5, 5.0, 15, 50, 150, 500, 1500 and 5000 μg per plate. No positive mutagenic response was observed. No precipitate was observed. Toxicity was observed beginning at 1500 or at 5000 μg per plate with all Salmonella tester strains in the presence and absence of S9 activation. Based on the findings of the initial toxicity-mutation assay, the maximum concentration to be tested in the confirmatory mutagenicity assay was 5000 μg per plate. In the confirmatory mutagenicity assay, the concentrations tested were 15, 50, 150, 500, 1500 and 5000 μg per plate. No positive mutagenic response was observed. No precipitate was observed. Toxicity was observed beginning at 1500 or at 5000 μg per plate with all Salmonella tester strains in the presence and absence of S9 activation. All criteria for a valid study were met as described in the protocol. The vehicle controls and positive controls in the initial toxicity-mutation and confirmatory mutagenicity assays were within the acceptable historical ranges and fulfilled the requirements for a valid assay. Under the conditions of this study, test article Dowanol™ TPnBH Glycol Ether was concluded to be negative in the bacterial reverse mutation assay.