Oxirane, 2-ethyl-, homopolymer, ether with 1,2-ethanediol (2:1)

Genetic toxicity: in vitro

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:

1/8/2013-22/8/2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Conducted at a GLP accredited laboratory

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

GLP compliance:

yes

Type of assay:

bacterial gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Oxirane, 2-ethyl-, homopolymer, ether with 1,2-ethanediol (2:1)

IUPAC Name:

Oxirane, 2-ethyl-, homopolymer, ether with 1,2-ethanediol (2:1)

Constituent 2

Reference substance name:

1-[2-(2-hydroxybutoxy)ethoxy]butan-2-ol

EC Number:

695-757-2

Cas Number:

897381-19-0

Molecular formula:

UVCB

IUPAC Name:

1-[2-(2-hydroxybutoxy)ethoxy]butan-2-ol

Test material form:

other: liquid

Details on test material:

Clear colorless liquid, stored in room temperature in dark

Method

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Metabolic activation system:

Araclor-induced rat liver S9

Test concentrations with justification for top dose:

In the initial toxicity-mutation assay, the maximum dose tested was 5000 microgram per plate; this dose was achieved using a concentration of 50 mg/mL and a 100 microLitre plating aliquot. The dose levels tested were 1.5, 5.0, 15, 50, 150, 500, 1500 and 5000 microgram per plate. The test substance formed clear solutions in water from 0.015 to 15 mg/mL and a cloudy solution at 50 mg/mL. No positive mutagenic responses were observed with any of the tester strains in either the presence.

Vehicle / solvent:

The test substance formed clear solutions in water from 0.015 to 15 mg/mL and a cloudy solution at 50 mg/mL.

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

methylmethanesulfonate

Details on test system and experimental conditions:

The vehicle used to deliver PD206 to the test system was sterile, distilled water (CAS No.7732-18-5, Lot No. 25055521, Exp. Date: May 2016), obtained from Mediatech, Inc.. Test substance dilutions were prepared immediately before use and delivered to the test system at room temperature under yellow light. The negative and positive control substances have been characterized as per the Certificates of Analysis on file with the testing facility. The stability of the negative and positive control substances and their mixtures was demonstrated by acceptable results that met the criteria for a valid test. Positive controls plated concurrently with the initial toxicity-mutation assay and the confirmatory mutagenicity assay are listed in the following table. All positive controls were diluted in dimethyl sulfoxide (DMSO) except for sodium azide, which was diluted in water. All subdivided solutions of positive control were stored at -15 to -40°C.
The tester strains used were the Salmonella typhimurium histidine auxotrophs TA98, TA 100, TA 1535 and TA 1537 as described by Ames et al. (1975) and Escherichia coli WP2 uvrA asdescribed by Green and Muriel (1976). Salmonella tester strains were derived from Dr. Bruce Ames' cultures; E. coli tester strains were from the National Collection of Industrial and Marine Bacteria, Aberdeen, Scotland.
Overnight cultures were prepared by inoculating from the appropriate frozen permanent stock into a vessel, containing 30 to 50 mL of culture medium. To assure that cultures were harvested in late log phase, the length of incubation was controlled and monitored. Following inoculation, each flask was placed in a shaker/incubator programmed to begin shaking at 125 to 175 rpm and incubating at 37±2°C for approximately 12 hours before the anticipated time of harvest. Each culture was monitored spectrophotometrically for turbidity and was harvested at a percent transmittance yielding a titer of greater than or equal to 0.3x109 cells per milliliter. The actual titers were determined by viable count assays on nutrient agar plates.

Evaluation criteria:

The condition of the bacterial background lawn was evaluated for evidence of test substance toxicity by using a dissecting microscope. Precipitate was evaluated after the incubation period by visual examination without magnification. Toxicity and degree of precipitation were scored relative to the vehicle control plate using the codes. Revertant colonies for a given tester strain and activation condition, except for positive controls, were counted either entirely by automated colony counter or entirely by hand unless the plate exhibited toxicity.
For the test substance to be evaluated positive, it must cause a dose-related increase in the mean revertants per plate of at least one tester strain over a minimum of two increasing concentrations of test substance.
Data sets for tester strains TA1535 and TA1537 were judged positive if the increase in mean revertants at the peak of the dose response was greater than or equal to 3.0-times the mean vehicle control value.
Data sets for tester strains T A98, TA 100 and WP2 uvr A were judged positive if the increase in mean revertants at the peak of the dose response was greater than or equal to 2.0-times the mean vehicle control value.
An equivocal response is a biologically relevant increase in a revertant count that partially meets the criteria for evaluation as positive. This could be a dose-responsive increase that does not achieve the respective threshold cited above or a non-dose responsive increase that is equal to or greater than the respective threshold cited. A response was evaluated as negative, if it was neither positive nor equivocal. the criteria for evaluation as positive. This could be a dose-responsive increase that does not achieve the respective threshold cited above or a non-dose responsive increase that is equal to or greater than the respective threshold cited. A response was evaluated as negative, if it was neither positive nor equivocal.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Positive controls validity:

valid

Additional information on results:

In Experiment B1 (Initial Toxicity-Mutation Assay), the maximum dose tested was 5000 microgram per plate; this dose was achieved using a concentration of 50 mg/mL and a 100 microLitre plating aliquot.
The dose levels tested were 1.5, 5.0, 15, 50, 150, 500, 1500 and 5000 microgram per plate. The test substance formed clear solutions in water from 0.015 to 15 mg/mL and a cloudy solution at 50 mg/mL. It is not uncommon to observe differences in solubility profile that vary slightly from trial to trial. These differences may be due to the volume used in the solubility test as compared to the actual assays. The Study Director has concluded that these slight differences had no adverse impact on the integrity of the data or the validity of the study conclusion since the precipitate and toxicity profiles were similar in each trial. No positive mutagenic responses were observed with any of the tester strains in either the presence or absence of S9 activation.
Neither precipitate nor background lawn toxicity was observed. Based on the findings of the initial toxicity-mutation assay, the maximum dose plated in the confirmatory mutagenicity assay was 5000 microgram per plate.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Confirmatory Mutagenicity Assay:

The results of the confirmatory mutagenicity assay were generated in Experiment B2. In Experiment B2 (Confirmatory Mutagenicity Assay), no positive mutagenic responses were observed with any of the tester strains in either the presence or absence of S9 activation. The dose levels tested were 50, 150, 500, 1500 and 5000 microgram per plate. Neither precipitate nor toxicity was observed.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

The results of the Bacterial Reverse Mutation Assay indicate that, under the conditions of this study, Precursor PD 206 did not cause a positive mutagenic response with any of the tester strains in either the presence or absence of Aroclor-induced rat liver S9.

Executive summary:

The purpose of this study was to evaluate the mutagenic potential of the test substance by measuring its ability to induce reverse mutations at selected loci of several strains of Salmonella typhimurium and at the tryptophan locus of Escherichia coli strain WP2 uvr A in the presence and absence of Aroclor-induced rat liver S9. All criteria for a valid study were met as described in the protocol. The results of the Bacterial Reverse Mutation Assay indicate that, under the conditions of this study, Precursor PD 206 did not cause a positive mutagenic response with any of the tester strains in either the presence or absence of Aroclor-induced rat liver S9.